Well I have TTI Stepped Headers we were thinking with 1 7/8 or 2 inch headers it would pick up another 20 HP, but for me the extra $800.00 would be crazy to spend for it when my headers only have Maybe 16 hrs total on them. So that would be Information for the guy who has not bought them yet!! Or maybe I will Sell them and put out the extra dough for the difference........