It sound like some lower gearing would help you out. What gears and tires do you current have?
I went from the factory single exhaust with converter to true 2-1/2" duals (still using the exhaust manifolds) with a crossover pipe and Dynomax Super Turbo mufflers on my 2WD '89 RC. If I remember correctly, (it's been a while) this only chopped two tenths off of my quarter mile time. (roughly equivilant to taking 200 pounds of weight out of the truck)
I went from the factory single exhaust with converter to true 2-1/2" duals (still using the exhaust manifolds) with a crossover pipe and Dynomax Super Turbo mufflers on my 2WD '89 RC. If I remember correctly, (it's been a while) this only chopped two tenths off of my quarter mile time. (roughly equivilant to taking 200 pounds of weight out of the truck)