if I was going to do a small chevy I'd go with the older style motor(57-87) and build a 383 it can be done for cheap (try performance automotive warehouse in CA the prices are VERY low and its all good name brand stuff) top it off with a good set of world products or edelbrock heads and either gm's ramjet fuel injection or a f.a.s.t. shop around for used stuff and you could probably do the whole deal for say 5k or so
hth