if its a 3 speed car don't run much more than a 3.73 if its going to see street duty
I've always been fond of quadrajets if your handy you build four or five of them all jetted different real cheap becuase most people will give them away then take them to the track or the dyno and keep the one that makes the best number you can find 750's and 800's on big block caddy's and old buicks