Johnny, It all depends wheather you have a warranty on the truck or not. I do and the mods I have are a K&N type filter and intake, a grannatelli mass airflow sensor model 350115C, A hypertech programmer (Using 93 oct. tuning) with the shift points set at +3 (1-2) +10 (2-3) +0 (3-4)mph. And a dynomax super turbo 1 in 2 out muffler. The main thing you want to do first is to get the air flow restrictions off the engine with the intake kit and exhaust. (You've got about the best muffler around so you got that part covered.)Those will make the most difference on a stock truck.

If your not worried about no stinking warranty <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> the you can just build up a 6 liter with custom heads, a nice after market cam, headers, and some cutting edge programming, and let it rock. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />