Chassis Build Up & Design

in your case, since you are using a bolt-on spacer, spacing the rotor isn't a big deal if you were to go that route.
you can make a donut and tap it and bolt the rotor to it if you wanted to.

Wouldn't need to be more than a few mm to get it perfectly centered and stay in the 1/2" plate range.

The calipers are quite tight to my wheels, so I might not be able to shave much if any off my 25mm spacers. Any change, in my case, would likely push the wheels outward.

I dont think you mentioned our discovery along the way about the budget fixed caliper option this opens up.

Turns out C6 shares a mounting pattern with 2015+ Colorado front brakes. These come with 4pot fixed calipers stock. Rock auto lists them for $75ea new no core. They're rough cast, not polished and not powdercoated, but also 25% the cost of the corvette calipers.

Don't forget they should fit inside 17" wheels too.

The Colorado uses a  26mm wide rotor which happens to be the same as the rear Corvette rotors. And the C6 Z51 rear rotors are the right diameter to use the same bracket bolt pattern as I did for the Z06 calipers & rotors. Plus they're cross drilled too, so your rotor will look just as fancy. The bracket would have to be 8mm wide instead of the 12 I am using unless you spaced out the rotors.

Spent Monday tidying up the last few things to get the body bolted to the frame.

Started by lifting the engine and transmission up out of the way, so I could snake the front passenger brake line under the engine. It runs on the back side of the cross member from the factory, but the oil pan resides there now with no extra clearance for a brake line. I was able to rebend the factory line and overall happy with the results. It now runs on top of the cross member and I am using an S10 hose bracket to clear my wheels. Similar to the situation I had on the Isuzu with the Blazer brackets; wide wheels crash right into them. Too bad custom tubing is pricey or I might have been tempted to design something up and send it over to In-Line Tube.

It looks like it is touching, but 1/4" or more of clearance on the driver side of the pan.



Plenty of space to play on the passenger side.



Had to play with this area quite a bit as I lost some of the length due to the original sharp bends in the Blazer lines.  I wasn't able to completely straighten them without breaking the line.



I had been chatting about the project with one of my coworkers and it pushed me over to welding in a flex joint. I just happened to have one I never used on the Audi, so it was a quick and easy job before bolting down the body. I liked how clean/smooth/pretty the y pipe was before, but this gives the play needed to easily bolt up both sides and should reduce some of the stress on the exhaust.



Some final shots before marrying the body. In the background you can also see I got the second pair of wheels/tires recently.







I also stopped by the shop last night for a couple hours. Made my new caliper bolt spacers and assembled the driver suspension corner. Was going to get the wheel on and on the ground, but had an early meeting this morning and still had 30 minutes of work left after pushing later than I really intended to.

Turned this cutoff piece of aluminum from one of my earlier projects into swiss cheese. I drilled 2 of the spacers over the edge as I needed a flat portion to clear the spindle on the lower bolt. I nailed it perfectly on my first guess, so didn't have to tune it in with the sander.





Definitely will work better than my flimsy first attempt using what was essentially sheet metal.





Everything fits great now and torques to the factory specification of 130 ft-lbs.



Driver side is ready for the rotor and caliper. Just have to load up the caliper with pads and bolt it on.



I think I'll clean up the engine accessories and get the water pump modified for a front outlet next, so I can get the front end sheet metal bolted on. I need to get the full weight of the vehicle to start setting ride height and torque down the control arm bolts.

Friday evening got the driver side caliper on and decided to finish getting the interior together. Moving toward steering column installation, so I know everything to avoid with brake line routing. It's finally supporting its own weight on all 4 corners.



Back at it Sunday. Started by cleaning up the carpets and getting the shifter and boot installed. Realized I would need to pull the boot to get at the shift handle in the future, so quickly cleaned that up and laid on some powdercoat. It's the Hurst handle from my NV3500 short throw, but had seen better days and I'm not the biggest fan of chrome.

The freebie powdercoat oven does a darn decent job. The temperature can be all over the place, but we've got an external temperature probe to keep an eye on it. Everything gets casters out in the workshop.



Friday night I had laid out the rubber shift boot/seal, drilled holes and added seam sealer where it touched off to the sheet metal for a bit of extra sealing surface. I got this boot from a 5 speed 4th gen Camaro and it fits around the stock Blazer shifter foam just right. If I'd had the boot before I cut the hole and repainted I might have cut the hole to fit it rather than the foam, but it all came together anyway.

Shift handle and boot installed. Don't mind the 5 speed knob as I haven't found a replacement knob I like yet. This will do for now.



Was looking back and realized I had no good shots of the S10e/EV1/GMT400 Diesel pedal I used with the drive by wire setup. Packages like factory maybe because it pretty much is a factory option.





Dropped in the carpet after vacuuming and lots of carpet cleaning solvent. Still super stained, but makes for a good practice piece to hack up and fit around my new shifter hole, PCM, and fuse block. I also didn't realize until the next day that my flash was on instead of auto, so several of these next pictures are a bit washed out.





TAC module is installed on the factory Transfer Case Shift Control Module bracket. The bolt pattern is so close it is silly, but with some creative positioning I was able to bolt it in with the wires pointing in the direction I'd like. It fits nicely underneath the kick panel.



Blower box and BCM still fit.





I had put the driver seat rails back on to test out which shift handle would work best. The Pro 5.0 was still a bit short much like the factory Camaro shifter and handle, so I stuck with the Hurst. Got the passenger seat together too and bolted them both in. Used a rubber mallet more than I'd like to admit in getting all the bearings back on the rails.

You can also see the passenger door panel that got installed at some point this weekend.





Seats feel great and with the short throw shift mechanism I'm quite happy with the location and throw of the shifter. Definitely didn't sit in the driver seat at multiple points this weekend making engine and shifting noises.

Whipped up a quick bracket to bolt in with the battery mount and hold the starter solenoid and vehicle fuse. Forgot to add a step up from the floor to help clear the carpet, but I'll want to powdercoat this piece in the future, so it will come back out at some point and I can modify from there. Probably add dimple dies too.







Threw in the rear carpet and bolted in the battery mount. Starter cable is the thick guy going off into the carpet on the right.





Added the battery and wired it into the truck. Made some sparks, so it must be grounded.  The whole package should fit in a battery box to make me compliant with most track rules. Not exactly sure what I'll do if I need an external cut out switch.









I'm realizing that nothing is sacred on this truck. Everything is going under the knife.

I present to you exhibit Belt Buckle:



The RSX buckle doesn't have the extra piece in the middle like the Blazers. Talking to a friend who works as an Engineer in seating and restraints I got the impression that the extra feature is really just a way to index different buckles in the vehicle and isn't a structural part. So now the Blazer buckles match the RSX buckles and I can use the latch attached to the RSX seats after some quick machine work and filing.



Finished off my Monday night getting the accessory bracket cleaned up and bolted back to the engine. Prepped the water pump mounting surface while I was at it and that could actually be the next step even though last week I thought I'd be doing that before everything else I did this weekend.







Also tore the wiring harness out of the dash, so I can get that modified before bolting the dash in. So close to having functional steering and an engine that can start with the ignition switch.

Started out the weekend with the IP harness. About halfway through I realized I had a pickup harness on the shelf that was already closer to what I wanted, but that's what happens when I've been collecting parts for years instead of doing anything with them.



After a couple hours it doesn't look much different, but pulled out the extra circuits and added in wiring for a switch panel to include the line lock, fan override, and quad high beams. I'm still not exactly sure how that will come together, but I've got a couple ideas on paper and all the circuits to pull them off.



And the evidence that something did happen:



While I had the terminals and crimp tools out I made a quick conversion harness for the RSX seat belt switch.





Once I hooked up the battery it functioned like factory.

I'm using the same Alpine component set in this truck as I did in the Isuzu. Mid bass in the doors and tweeters mounted in the factory tweeter plates. Clamped the plates on the Bridgeport, enlarged the holes with the 2" hole saw, and the tweeters pretty much screw right in.



I don't expect it to sound as good as the isuzu without the sound deadening treatment, but will be better than the factory speakers.

With the speakers and harness done I put the dash back together. It still installs even with the PCM in place, but I did have to unbolt the fuse block. I also had to give it a bit of a shove toward the driver side as my modified steering bracket still locates the dash cross car. It went together and the doors close, so the shift toward the driver side wasn't the worst decision I've made.



I recently learned of a trick to reverse plastic panel fading, so I gave it a shot on my driver door panel. I was originally planning to hunt down a set of 02+ panels with the microfiber cloth to better match the seats as my panels had some issues, but after grabbing a replacement armrest for the passenger side and learning of this trick. I'll save my time and money unless I find a really mint pair.

Here's typical white sun fading found on many of these panels. It's actually not terrible on mine. Definitely seen far worse.





Apply heat slowly moving around the area until the plastic remelts and changes back to the original color.



I melted it a bit more than I should have, so it is a bit more glossy than the rest of the panel and some of the grain washed out, but definitely less worn looking than before. Next time I will turn down the heat settings instead of maxing them out and go more slowly.



It didn't take me much more than 5 minutes from start to clean up. There are YouTube videos on the process if you want to know more.

Steering column is in too now. Really starting to look like a complete vehicle on the inside. Wheel is just set on the splines for now as I have a new column switch on the way.









With the column in I also installed the steering shaft. Lots of room to the manifolds, but looks like I need a longer or right angle spark plug wire for the rear cylinder.





Decided to crimp the power wires and hook up the battery for a test power up. The only harness remaining is the forward lighting, so it was a bit nerve wracking adding 12v to all these wires for the first time, but nothing exploded and no fires in the meantime.



Half of these lights are no longer needed. Time to start pulling bulbs. Also don't mind the temp gauge. Not sure how that happened.

The only electrical issue I've found so far is the tail lights. The fog light is the only non functional circuit right now and that's because I have the wrong fuse block installed, but the passenger side brake lights aren't as bright as the driver side. Will need to investigate that the next time I'm out at the shop.



The 4.3 brake booster vacuum line isn't quite long enough to reach the 5.3 port. I did some looking around and the V8 Trailblazer seemed like the best fit. Both the SS and the 5.3 version use the same hose, so I ordered one up with one of my orders from the dealer and had good results.





It doesn't exactly fit like it was made for it, but no one will ever be able to tell now that it is installed.



I only had to cut off about this much from the engine side.



Next up I tackled the water pump. I'm not a huge fan of the truck pump inlet location. Fortunately the older pumps have a boss in the same location as the LS1 pumps and a few people have pioneered the conversion.

http://ls1tech.com/forums/conversions-hybrids/1630719-truck-waterpump-converted-f-body-3.html

Al and I had a spare pump we did some practice on and had varying luck removing the hose barb. We ended up using heat, but it was a fine line between warming it up and melting it. I was already needing to bore out the hole 50 thousandths for the freeze plug I was replacing it with, so I decided to just remove the barb in that fashion instead of risking another meltdown.

Step 1: Sawzall

Bye Bye Nipple





Step 2: Level water pump and bore hole to size





Step 3: Drill, ream, and tap front boss.



This was a bitch. Al had trouble on the practice piece without the ream and I was still using a 4 ft breaker bar to get the threads in deep enough. Large size NPT taps are no joke, but I never found a great solution on the internet even though some people "do them all the time"



Step 5: Slap in the new barb and freeze plug with sealant





Went to install the water pump and was only able to find one of the old gaskets. It was also falling apart. Should have dug those up last week, so that's another part on order.

Bolted it on anyway to see how my hose selection fit. Top hose fits great. Bottom hose is too big on the radiator size, but that may be something I have to deal running the radiator I am. Found another hose on the shelf that clamped down decent to the radiator and I was able to squeeze it onto the water pump. I'm going to look around some more as I'm not completely happy with it, but I do have a solution.





Grabbed the power steering hoses from the 4.3 and they bolted on without much fuss. Got creative with routing, but good clearance to everything so far.





Last thing for the weekend I started tackling the brake lines from the master to the rest of the truck.

First up was to mount my line lock and prop valve. It's actually coming together quite nicely as the line lock will also serve as a T for the front brakes and I whipped up a bracket to mount both valves right on the booster. I'll need to space out the line lock as there isn't a ton of room behind the bracket to the brake booster, but I have a couple ideas already. Will add some dimple dies and powdercoat once I have it finalized.









Mockup of the original lines was looking optimistic without needing too many bends.

Great progress. Those front tires do it for me every time I see them...

The heat gun trick works reasonably well - I've already done all of the faded outside trim on the old Jimmy and it definitely helped a lot. I only melted one small section on my first try. Oops.

Great progress. Those front tires do it for me every time I see them...

Me too. The back pair may be one of the last things to go on the truck. I've been dragging my feet on the machine work for the rear calipers, but everything else is coming together quite well, so I'm just letting it happen haha

good progress!

as for the water pump, you already bored it, should have just shoved in the original neck.
I've had good luck just heating up the WP and the loctite releases and aluminum expands just enough for the neck to basically fall out.
im taking notes on the brake booster line and hopefully the coolant line selection carries over to my swap well too

good progress!

as for the water pump, you already bored it, should have just shoved in the original neck.
I've had good luck just heating up the WP and the loctite releases and aluminum expands just enough for the neck to basically fall out.
im taking notes on the brake booster line and hopefully the coolant line selection carries over to my swap well too

I had tried that with the junk pump originally before melting it trying to get the neck to release.

This sounded good on that thread harley linked above. We own the tap and ream tool now if you want to go this route too.

Given we were using the oxy torch; map gas might have been a better solution with the lower heat output, but didn't want to risk melting my good pump too. I also wanted the straight neck and didn't have much luck finding a part number for the neck sans pump. Would have definitely preferred that as it looks less modified.

Like Al said, we have the tools and the Bridgeport, so whatever you decide to do with yours we can help out.

I may have much of the cooling system together tonight. Pump gaskets are showing up at the least. I did find a pressurized reservoir I like, but plenty of options even in just the GM car section at the junkyard. I'm mounting mine somewhat where the original overflow mounts, so you'd lose the PCM mount, but I guess if you're getting rid of the original reservoir you're losing it anyway.

Stopped out to the shop for a couple hours last night. Had about 27 packages showing up, so did some easy bolt ons and mockup to keep progress moving.

First up was the water pump, which included the remaining pulleys I needed to slap on the drive belt... apparently in all the write-ups I'd gone through I forgot or missed the fact that they weren't using the factory truck belt routing. 





Back to the drawing board today and I'll be moving the idler to the top accessory bolt below the alternator. Will need a 20.5mm spacer with a 30mm OD, a 160mm long M10x1.5 bolt (GM part number: 11518249), and a 103" belt.

Will end up looking like this:


Next up was the Trailblazer V8 (SS or 5.3 use the same) spark plug wire. It has the wire coming out 90° to the plug boot and gives just enough clearance for the steering shaft. Very clean solution. It's real close, but fits.





Threw the next lower rad hose trial on.



The diameters are spot on for both sides, but it ends up getting a bit twisted and stretched. Will probably work fine, but I'm thinking about extending it some or piecing together some different hoses with a reducer. It's the lower hose, so the split won't be so obvious to anyone looking in the engine bay unlike the upper.

I ended up cutting off a bend to get it to line up correctly, so no returning this hose. If the rad were closer to the engine I'd probably call it a good fit, but that's not where my mind is.



The upper radiator hose that fits is Dayco 71751 for future reference.



Lastly I made a quick converter to mount the billet shift knob I picked up. M12x1.75 is the knob pattern and the Hurst shift lever is a 3/8-16. No one makes an adapter because the threads are super close, but I took an existing M12 bolt and centered it up on the mill, drilled, and tapped with a small amount of drama. I'm very happy with the results considering I didn't want to put hours into this.



Also installed the cruise control turn signal lever that was delivered and put on the column covers. I'm holding off on the steering wheel to make it easier to install the radio and pull bulbs on the instrument cluster.

Such a well photographed build thread.

Been picking away at this over the last couple weeks and had high hopes I could have it on the road or very close to by the end of this 4 day weekend I had, but ended up spending most of the weekend wrestling with brake lines and trying to get the rear parking brake and caliper adapters figured out.

Accessories turned out as expected with the pulley relocated. Al found some round aluminum stock on Amazon for a great price, so a quick cut and mill to height was much easier than the sloppy hole saw method I was starting out with. 1 1/4" diameter was close enough to 30mm to work and the 20.5mm height was pretty much spot on. The 160mm GM bolt I sourced was the right length and diameter, but the bolt head was smaller than I realized, so I threw a washer in there to make me happy.



Last week I did some digging around the GM parts catalog to turn up any and all LSx lower rad hoses I could find. Both C5 and C6 vettes had potential as far as both shape and going from a 1.5" hose on the water pump to a 1 5/16" at the radiator. Dayco offers the same hose (71983) for both applications even though the C6 is more of a straight shot. For $15 I wasn't going to make a big deal about the extra bends and it fit perfect with about 1.5-2" of trimming on the radiator side.





I'm not sure why I hadn't looked at the GM parts before.

One weeknight Al stopped out and we started sorting through the rear lamp electrical. It must have been a late night or I wasn't in my right mind when I wired those into the body harness because I botched a few things, but after reviewing many of my other circuits nothing else is out of place, so far. A couple of the major connectors I must have been looking at upside down when I added in the wires and even had a ground going into the fog lamp circuit at the tail light, which was giving me varying brightness between the different brake lights. I also needed to swap in a pickup underhood fuse block with the CHMSL relay and a body relay block with door lock relays that I am using to switch between fog lights and brake lights. The rear lamps work as they should now. Well other than needing to reprogram the BCM to work with the fog lamp switch.

Lower driver rear fog lamp lights up by itself for my rear fog setup.



But once I hit the brakes they all light up



I'll have to do a video at some point to show how it all works in action.

The rest of the weekend I wrestled with brakes. All of the plumbing is done and I'm pretty happy with how all the lines came out with the master, line lock, and prop valve. I didn't grab any pictures as I'm waiting on the 1/8" NPT fittings I need to convert the line lock to 1/4" inverted flares. Of course they're special order everywhere I've found them, so hoping McMaster Carr ships out today or tomorrow or who knows when I'll actually be able to get my hands on them.

At the rear I was trying to keep the parking brake mechanism, but the drum in hat on the rear Z06 rotors is further outboard than the S truck rear discs. No big deal just space it out the 21mm, right? It was all looking great with dust shields I cut down on the mill and cleaned up the rust before paint.



Al will appreciate that one of our micrometers actually got used for once.







That is until I went to install the axle shaft and I couldn't access the slot for the C clip... I ended up taking the spacer down to 16.5mm after trying a few other things and that gives me enough room for the c clip and the parking brake pads still appear to be on the drum in hat. It isn't centered like it would be from the factory, but simply being a parking brake it isn't likely to be a huge deal. At least for me. It is definitely a tight fit, but the axle shaft will not be able to move inboard much once the center pin is in place. If it could I'm more worried about the c clip falling out than contacting the parking brake mechanism.





Had to leave the axle only half together with only the one spacer setup so far.



Back at it a couple nights this week and hoping I can have the axle in one piece again before the week is up.

The attention to detail is amazing. Damn close now!

aww still not done!?

that looks more like a macrometer than a micrometer.

glad things are coming together, but the taillights are the perfect example of Harley being Harley and over complicating something that could have just stayed stock

Ha! The tail lights were on the easy end of modifications from stock. I might have a couple hours into them total with troubleshooting. I realized the other night that if I would have just bought stock rebuilt rear calipers I'd probably be on the road already. I'm sure I'll have somewhere between 50-80 hours into the machine work for just the caliper brackets.

Also that's one of the smaller micrometers in the set we have, which actually works out alright as they start where the dial calipers end.

I've been picking away at the second spacer on my free evenings this last week. Got it mostly roughed in and realized the mill head wasn't completely straight, so had to get that sorted out and do the outer bore again. Everything went smoothly after that.

Rough shape of the spacer looks like this. I turned the OD down to 74.98mm to sit inside the factory caliper bracket, but it helped to take the majority of the meat down with an end mill rather than the boring head.



I opened up the bore to about 69mm to clear the axle housing and give me space to work with the boring head on the OD. I ended up heavily modifying one of the boring bits to be able to use it in this manner with a grinder. It was already chipped from its normal use, so this was reuse rather than trashing a good tool.



Took awhile to get this all milled only moving in toward the OD at 25 thousandths of an inch per pass.



This is where I noticed everything wasn't straight, so I trammed the mill and took it down again to the lowest point.

The finished product:



Had to flip it over and bore out to 75.25mm for a snug fit over the axle flange.



Milled down the edges to the shape of the axle flange. Fits in the caliper bracket exactly like it should.



And on the axle flange





The 16.5mm instead of the 21mm thickness I originally planned isn't as bad as I thought it would be. CAD shows the parking brake pads are still fully within the drum and I can easily get the c clips on and off. I'm happy.



Now to pick up new axle seals from the dealer, check the wear on the axle bearings, and get this buttoned back up.

you do a lot of boring stuff.
but the part looks great!!!
glad to see you are doing peripheral stuff to let me catch up!

i was looking through some old threads to dig up radiator info and came across this gem of a quote

I like how you kept going even on reduced power. 

I have some interest in the tires, but it won't be strong until the Spring and hopefully we'll both have v8s by then.

look at that date!
http://www.pro-tourings10.com/index.php?topic=176.msg1366#msg1366

The boring head has certainly earned it's keep on the Blazer. I was even using it as a fly cutter until I picked up new set screws for our actual fly cutters. I'm getting better at the machine work, but not much faster yet.

Haha to that date. Al and I realized earlier this summer that the engine has been out of a functioning vehicle almost twice as long as it ever was in one and Blazer has been in pieces for half the 10 years I've owned it. 

So this weekend I put some things together 



And took some things apart 



With the axles out for the rear brake upgrades I did some research on wheel bearings and axle seals. Came across a how to from Hot Rod on bearing relocator kits and learned what to look for in axle wear. Turns out my driver axle is a classic example of bearing wear on a GM 10 bolt.



Bearing was quite pitted as well. I grabbed the spare 8.5 rear end out of the field, beat off the super rusty drums, pulled those axles only to find out they're just enough longer - we're talking 4.5mm - that my parking brake shoes are now sitting partially outside the drum. So I said screw it and pulled the whole rear. It is now at Drive Train Specialists in Warren, MI waiting to get the TrueTrac differential I've always wanted installed with the 3.73 gears I've had sitting on the shelf. I'm waiting for them to give me a call with my axle options, but I'll probably go with a stock replacement unless it is within $10-15 of the extra cost for a Moser axle.

Brake lines are all bolted up now along with the powdercoated line lock and proportioning valve bracket.  Used Al's master cylinder bench bleeding method beforehand. Basically loop brake lines back into the reservoir and pump until the bubbles stop.









Started on the rear caliper brackets too.

1" plate + machinist blue



paper template



insert too much time cutting, grinding, and wishing for a CNC plasma table or even a functional bandsaw



I said rough cut, right?

Rip down to .774" thickness and rethink my decision not to use 3/4" plate. I also miss machining aluminum at this point.

I'm getting a pretty nice surface with a flycutter though. Lots of practice.






Next up I slap the two pieces together and drill out the holes. This is the step that makes or breaks the brackets. Everything else can be tuned easily enough.





I bolted the 2 pieces together, so they don't move around and started milling down the edges before I left the shop last night. Al reminded me we have some serrated hogging bits that may work better, so hopefully I can speed this step up a bit.



The front end got assembled at some point over the weekend. I wanted to get a start on the cooling system routing. I actually have everything in place other than the reservoir and waiting on getting the inner fender mounted before making the brackets for that. It's all just loosely in place. I think I want the truck with the weight on the wheels and the hood in place before I get everything lined up and tightened down. Also hooked up a few misc things: a few harness connections, vacuum lines, hood cable. Basic stuff, but real progress on a project this torn apart.



Heater hoses are pretty simple. I'm pulling the reservoir/degassing tank off the heater core return. That's the top part of the T going nowhere at the moment.





My goal is to have the brackets 2/3 of the way done on my 2 evenings out at the shop this week. If I can get those wrapped up by the end of the day Saturday I'm fairly confident I can have the engine compartment in place by the end of the weekend. Another day for lamp wiring, install the rear, bleed brakes, clutch, coolant, and the truck is pretty much on the road.