Ok first I'd try to find a 6 speed tranny out of a Camaro or Vette, that'll give you the high speed ability to cruise down the freeway. Then I'd use a 3:73 posi. Get some wider tires out back like 9" or 10", also put some meat out front for good cornering. Next depending on the money wanted to spend, I'd go with a Crate 350 thats full roller, and reds at around 6,500. Pushing around 400hp, thats the cheap method.
But if you want to go all out put this in there,
Thats a Schubeck 904 CC aluminum block, 4 valve per cyl, DOHC 1200HP engine on pump gas no turbo,no supercharger, no nothing just power
But remember without traction all that power will be wasted, with RWD street tires you won't be able to hook up at the line, and tubing and drag slicks are cheating, and don't count because it's not street legal. So AWD conversion is where its at with this motor, thats if you want a near unbeatable street fighter.
be careful about underestimating ricers, for the most part with a nice step-up you'll be able to beat them, but there's a few out there in every town that are nasty, you must remember we're fighting alot of weight, and there not, some of the new AWD ricers that are coming out are pushing 280hp from the factory, and are not to be messed with. There the ones that'll leave you talking to yourself.