My 414 Duster has a Comp flat tappet with specs of 242/250, 106 lsa, 107 ic installed, weighs 3300, 3.55 rear, 28" tires & 4 speed. Makes killer low end & mid range but is done @5400. I have FiTech efi, air gap intake. Timing was locked out @ 34 degrees & was a dog on the low end with a carb...