78 with 2f, I'm switching to a 12si alternator. Since A/C is one of the items on the list, I also picked up the vintage air dual bracket for compressor and GM 10/12si, vintage air part 158209. I test fit it, and the result is a 5/8" face offset, with a 3/4" groove center offset. Picture below. I just ordered a 2 groove replacement pulley which combined with a 1/8" shim should get me even with the crank and water pulley. I've done a few searches, and normally I'd take more time and search for a while, but I have an added complication. I'm going to temporarily (but possibly permanently) lose my forward shipping capability effective 1 November (I'm in Riyadh). I really need to get whatever I order in the mail in the next couple of days or I am going to be stuck trying to find a solution in Batha market.
If anyone has used this bracket and come up against the same issue, Please let me know if you have come up against the same issue, and how you solved it. I think the double pulley and shim will work, but if you know a particular offset pulley for the 12si that works for this or some other solution, I'd love to hear it. I'd rather order two solutions and deal with leftover parts than only have 1 and find out too late that it doesn't work.
If anyone has used this bracket and come up against the same issue, Please let me know if you have come up against the same issue, and how you solved it. I think the double pulley and shim will work, but if you know a particular offset pulley for the 12si that works for this or some other solution, I'd love to hear it. I'd rather order two solutions and deal with leftover parts than only have 1 and find out too late that it doesn't work.