Your least expensive route would be to go with 16" wheels and a 3:55 R&P, and rebuild your engine. If you want to spend a lot more money, the options are endless.
Forget fuel injection... that engine doesn't have individual intake ports so even if you did find a way to add FI, the return wouldn't be worth the effort and expense. Add dual exhausts, electronic ignition and a small 4-barrel carb, and leave everything else stock.
