I think you could make lots of horsepower by using more exclamation points.

Seriously, though, you're going to have to be more specific about your goals. How much power do you mean by a lot? Do you care more about the horsepower number, or about how quickly you can run the quarter mile?

You're seriously limiting yourself by ruling out nitrous, superchargers, and turbochargers. They are called "power adders" for a reason!

Pretty much the only option left is heads+cam and/or increased displacement. Neither of those is particularly cheap. What sort of budget are you on?

 

It's not all about haveing a hot engine. Let's say you get that sucker to pump out 500HP and 500Ft.Lbs of torque. Do you need the trans to get you all the way down the track? Because your stock one won't. That driveshaft isn't going to live too long either. And that 10 bolt rear axle, kiss it good bye. Your stock fuel system isn't going to feed much of an engine either.

Ok, so you get the engine, trans, and axle build up or replaced so nothing breaks, how about getting that power to the ground? Stock suspension pieces might leave the axle laying somewhere behind the car after a hard launch. Don't forget the subframe connectors so you don't twist that car up.

Cubic dollars my friend.

 

A Set of Trick Flow heads will run you up only about 400bucks more then nitro, and you won't have to refill your heads, (good for 50-100hp)depending on what your are working with.

While you are at it get a cam, 220dur range for easy with carb

auto... get a converter (my opinion 3000 min.).3-.70 tenth of 1/4