A/C Compressor Replacement

[85/Silverado]

I'm having trouble finding the proper A/C Compressor for my 85 Silverado.
I had a estimate to replace mine at a small shop and they said $790.00.
I about fell on the floor, that was $200.00 off since they fixed the leak in the lines that I had and won't charge me to recharge the system again.:
. It took 4 different places to fix that so it cost me to refill the Freon 4 times at $70.00 a shot.
I tried a couple places on Ebay to find the compressor but they were a little stumped. Here is the last answer I got.

"Thanks for the inquiry! Yes, there will be a difference. If you look under product notes in the compatibility table there are differences in the diameter of the pulley, number of grooves, and the position of the connector. Unfortunately I can't tell from the VIN so you would have to look on your unit and compare it to the notes on the following units:

7511246

7511247

7511357

7511369
Unfortunately I don't stock all of them but if you type those numbers into eBay you can at least read the descriptions."
I tried typing those numbers into google and got nothing to do with my compressor.


Here is a picture of my compressor if this will help. My clutch dosen't kick in so I need to just replace the whole thing since I'm not a mechanic.

Thanks Guys
Jack