Any idea what application the 4 groove pulley you used was from? I don't have any in my spares and I'd hate to play the guessing game with buying online if there's like 57 different 4 groove pulleys out there.
This is speculation and fuzzy memories (crap, I'm getting old) here, but I vaguely recall that 80s 318 M-bodies with A/C and smog pumps had weirdly-complex multi-belt drives. I wouldn't be surprised if trucks and vans may have also used something similar.
