Well its like this,
With the shock mod and possiblely due to a little extra torque (I suspect 98% removal of shock and MAYBE 2% additional power related) I can't keep the wheels on the ground. That means all the power sent to the front wheels is wasted. When I mod the rear of the truck with a beefer suspension that enables me to run 1 shock on each side properly so that the truck support the Gs under acceleration, I will be in a better posistion to observe power gains. Right now its not the right time to look for that. I am sure there are power gains, because removing that constricting stock header could only help. The stock pipe is huge, so I suspect some weight savings there (Every little bit helps). I can say currently the truck runs better with the new exhaust. No 1/4 to 1/2 tank stall issues anymore. That tells me it provides more back pressure and it idles a touch smoother. I have seen longer runs, but I can't tell if thats because I am used the the 1/4 tank issues that seems to have cleared up with the new exhaust, or if the new exhaust extended the run time due to better fuel use.
This weekend I will be able to provide more feedback on the exhaust as I ordered every thing I wanted to try for the rear suspension. I decided to run some LST shocks on the rear (Thx to Scott_GTR for the input) with the most stiff spring I could find (8.3lbs). Once I get that fitted correctly I should be planting the power to the ground and will be able to correctly observe the trucks performance.
So hang in there and give me to the end of this weekend and I should have some good feedback for you, supported with some pics and a part list of what I used to do it