It depends on which compressor you have- I think they had 2 or 3 different ones. I actually pulled an entire system off a '78 that I was going to use on my '67- FE big block. I ended up going with Vintage Air instead, so didn't use it- but would probably be better off selling it as a complete set rather than pieces. I never tested it, so not sure it's any good either... Have you priced out a new clutch for your unit? I don't recall them being that expensive?