DS??? Do the Underdrives make a difference, i was told they dont in the 4.6, like they did in the old pushrod.

Have Cervini's Upper and Lowers, Roush Spoiler, Intake, N2O, SCT Tuner, Shifter, Magnaflow Ex.

I will most likely go with gears, a speed shop/race car builder around here gave me a $500 quote installed, which is a great deal. Would like to go with an H or an X, still undecided which.