you need to figure out what you want fuel inj. or tbi or carb. because fuel inj. requires a certain lobe separation on the cam grind to work efficiently. more room to play with cam grinds on carb set up. There was a early model 4.3 that was carbureted that had a standard hei distributor that would work. I think I've seen them in early model S10's I'll try to double check.
