As you may or may not know the A/C system has several component: compressor, condenser, accumulator, hoses and a dryer.  All of the components except for the accumulator are easily bolted off and the compressor needs to be replaced with an idler pulley.

As a note it is legally required to capture the freon removed from the system in a prescribed manner that I don't know of.  If you don't either take it to a shop...

Blower Box
The accumulator is part of the blower box assembly on trucks with A/C.  Trucks without have a smaller box that may be hard to find at a junk yard.  While that is the cheapest way to get one I have also listed the dealer part numbers below if one cannot be found.  They can also be purchased at gmpartsdirect.com for possibly less than the dealer prices I listed.  Aftermarket blower motors are also available at part stores.  You will need all four to correctly install the box.  The same bolts from the original blower box can be used to install this one.  There is one bolt behind the motor that will be hard to get to.  Jacking up the back of the transmission to rotate the motor forward and or using a ratcheting wrench will help get it out.  Removing the passenger fender helps too.

Case: 52474409 - $66.46
Gasket: 52457440 - $12.37
Motor: 52498879 - $71.04
Vent Tube: 03035192 - $9.82

With compressor and blower box still installed on my truck.


Compressor gone and new blower box installed.


Idler Pulley
There are several options available here based on ease and cost.  The easiest and cheapest is to get a A/C delete bracket.  It is a bracket that bolts in place of the compressor and has a pulley the same size as the compressors.  It should use the original belt if purchased for the year of the truck, but you will have to find 3 much shorter bolts to attach it with.  There is the slight possibility the belt will be the wrong size.  Usual cost is about $30-40.  I got one through summit and also got one through Advance Auto at about the same price.





The next option is to use a stock style idler pulley that mounts on the front of the compressor and power steering accessory bracket.  This is the best option for those with hood clearance problems.  It can be had from the dealer or gmpartsdriect.com using p/n 12580772 (~$50 from dealer).  This part number should come with the required hardware.  They can also be purchased from rockauto.com or a local parts store for about $15 if you're willing to use an aftermarket pulley.  It is listed as a grooved idler pulley.  You will have to get the mounting hardware from the junkyard or another source as well .  The OEM smooth idler pulley uses the same mounting hardware, so this can be easily found.  Although if you are already at the junkyard the grooved idler pulley is also used on the tensioner for these motors.  Remove this and nab the mounting hardware from the idler on the same motor for the cheapest way to get the smaller pulley.  With any of the stock style pulleys I suggest picking up a belt for a non A/C pickup from the local parts store.  Belts from the dealer are $50+





The last option for the idler pulley is to just bypass the compressor.  I don't suggest this since any loss in tension could have your belt catching on itself moving in the other direction, but all you need to do is run a string across the belt drive and measure it to find your belt length.



I suggest going with the OEM ribbed pulley.  Personally if I were to do it again I would go to the junkyard and get one off the tensioner.  Even the 140k pulley off of my original motor spins easier than the aftermarket pulley I ended up getting.

To me? No. I just want heat and no leaks. But i though that as long as im in there...

Yeah you can keep the A/C blower box with the accumulator inside and everything will still function fine.  I did that for awhile.  It is pretty much like having a broken A/C system.

I still think if you are not going to fix it there are other great advantages to swapping to the heavy duty heater box like extra weight savings and more room under hood for tires or a turbo or a V8 or dream even bigger.

It isn't too bad of a job.  Pull the bumper, pull the fender, and you have easy access to everything. 
A ratcheting wrench for the nut behind the engine makes it better, but I've wrestled through without.

I know there is a combination of bolts and studs coming from the heater core if that is what you are asking.  And yes they can be a pain, but I've been able to get them done pretty easily regardless.

You pointed out the biggest issue with that.  There won't be enough wrap on the alternator.  And now that you mention that the last example is also lacking a good wrap especially with that long unsupported section of belt.  With a good quality bearing that extra pulley won't be a huge issue.  Sometimes (and more often than not) the OEM's do know what they're doing.