Smoke20, how brave do you feel? lol. You could always "crimp" or "kink" the exhaust somewhere to gain a little back pressure. Its dangerous to do this cause if you go too far you can't go back without new pipe. I did this with my 91' when I straight piped it. Right were the cat was I took a little vise and crushed the exhaust in one spot, just enough to choke it so it would actually move when you mashed it from a dead stop. (This was before all the mods). It had a 2 3/4" pipe all the way back, overkill for the old tbi motor.

 

I thought about getting some of that flexible exhaust pipe as well, and then putting an adjustable clamp on it to test. This way I could tighten and loosen and test. Just no time now, work sucks ***, and busy season is still 6 days away.