Dont go nuts until you have done the basics..............a good tune up....better air filter, so it will breathe, better exhaust, so it will breathe.....................maybe, headers, so it will breathe...............Bigger cam and carb, so it will breathe............better heads.................See a pattern emerging here?

An engine needs to breathe to work well.

If you want better accelerarion, stiffer rear end gears are the way to go, but take into account, your mileage will suffer................

An engine rebuild will also help, if needed.

Those are the basics..............then you can get the nutty stuff like NOS and blowers etc.