The Stock Gm compressor is designed for a COnstant pressure system and really should not used in a Cycling system ( Vintage Air ). You can have the GM compressor converted but I don't know anybody who has had one survive or not leak its guts out.
We use the compact AC compressor in the stock location. But we also adapted the Corvette bracket system to the LSA drive system to move the alternator up and away from the rack n pinion. It actually was pretty easy.