I have a 4.8 Vortec from a 2004 GMC Sierra 1500 in my 76 Ford F100 and I need to installed the AC soon, is getting hot. I do not have the original compressor from the 04 GMC but I have an AC compressor from a 2000 Chevy Silverado, can I sue that comrepssor or do I need to buy an aftermarket compressor. If I need to get an aftermarket compressor can someone tell me what brand, I need one with 4 groves pulley.

Thanks for your help

 

anyone,

 

Dont take this as the gospil, but looking at the catalog, 99 - 02 was one style compressor. Probably Vortec. And 03 - 10 is another style, probably LS style. I would get the bracket from a wrecking yard and then buy a truck compressor for your engine at a parts store.

Anyone else have an idea?

 

I have the truck compressor bracket and A/C compressor off of my '04 LQ4 engine, in case you need and or all of it. The engine had 58k miles and the A/C worked fine when pulled a couple of months ago. I have both A/C lines still on the compressor. Let me know if any of this will help you out.

 

I have both bracket for the 2000 silverado and for the 04 GMC Sierra and both of them are the same. I have read before in some of the threads that you need to get an aftermarket AC compressor because the original compressor does not cycle, or something like that, thats why I am asking, but if I can use the original AC comrpessor I can try the one I have.

Thanks for your help

 

I think you're referring to the variable vs fixed displacement compressor. A lot of people with aftermarket AC systems face this.
All the truck compressors, except Trailblazer SS, are variable displacement. They are made to operate at different pressure vs fixed. A 76 ford would be fixed. The variable compressor do work, but it seems not as efficiently as they should.
I'm also guessing you're ford is still R12? If so, you'll want to convert to 134. I've heard those conversions decrease efficiency too, so the combination might be a bit weak.

 

Thanks garys 68, but can I install the AC compressor that I have from the 2000 SIlverado, or do I need to buy a new aftermarket compressor. I am changing to the 134 system. I check some Sandem but it apperas that I have to use those with an aftermarket bracket.

 

It will work but the binary switch controlling the compressor on/off cycling wont be in the optimal rangs. If it gets hot there in the summer and your AC isn't working very well, that may be the problem.
The other alternative is the Trailblazer SS which is supposed to fit in the same stock location.

 

Interesting - I thought the early Vortec truck compressors were fixed also - your saying only the Trailblazer SS is fixed? I face a similar dilema - LS1 compressor on a VA system and had planned on going with a Vortec fixed-displacement just to avoid any issues. If the compressors are physically the same it would seem that the variable could be modded to a fixed? Thanks. -Bob

 

I was told that the difference between the compressors was that the variable compressor was used for climate control and the fixed was for conventional AC. Not 100% sure of this, maybe some else can verify this. I used a GM factory fixed displacement with my Vintage Air. They said the variable displacement would not work on their system.

 

Jim, what year/model exactly did you use? -Bob

 

When I bought my Vintage Air and Classic Auto Air, I checked on compatibility. I found a few threads here and other boards where people have use LS1 variable displacement compressors. Results were mixed. Both companies told me of issues. I ended up using a Sanden.
I ran across a thread here that indicated the trailblazer SS compressor is fixed displacement. IIRC it has "TRSA12B" on it.
Do a search here.
https://ls1tech.com/forums/conversio...will-work.html
https://ls1tech.com/forums/conversio...ble-fixed.html
https://ls1tech.com/forums/conversio...e-air-kit.html

 

Thanks for all your help, this AC stuff is kind of complicated.

Garys 68, you mentioned you end up using a Sanden, did you use it in the stock location. I dont mind using a Snaden as long as I can install it in the stock location, otherwise I have to buy a bracket, and the most economical is about 200. I have plenty of clearance between the frame and engine. If you use it in the stock location, what Sanden model you use.

Thanks again, summer is getting closer and I want AC

 

There's a bracket to keep the Sanden in the stock location. It was under $100, I think. There's a link somewhere here in the conversions forum. I'll post a link if I can find it.
Saved in my favorites:
http://www.hhclassic.com/scripts/Par...lle&KeyNo=1471

 

I don't think all the truck compressors are variable. The compressor that came on my 2008 LY6 is a fixed displacement compressor.

 

Gary 68, thanks again, also, my engine pulley for the AC compressor is 4 groove, is that what you have, can you get the sanden 508 with the 4 groove, I am finding only 6 or 7. I check the bracket and I will probably get it.

Thanks

 

You just use to 4 groove belt, you dont need all 6 or 7.

 

garys 68, so I can use the 4 groove belt on the 6 or 7 groove AC pulley, they line up, i did not know. Thanks for the info