You said that the wiring scared you away from the Ls, that was what scared me out of a steal of a deal 98 Ls1 when I started my build. I still kick myself for that one Anyway, go with the 350 unless you find a 400, which are not as plentiful. If you say you have limited money for this, going down in cubes doesn't come close to making sense. I've been around gen 1 stuff my whole life and not once have I ever seen or heard of anyone building a 305 or 307 because it's a waste of money. As said before its a smog motor, a puke motor. You can google all the specs you want and argue but it doesn't change the fact it's a paper weight. As for the trans, the TH350 would be fine unless you have some short gears and plan on some long interstate driving.