The full kit cost about $350, the intake and carb were about $400, and I think I have 2.12" intake and 1.54" exhaust valves. Whatever the biggest valves that can be fit in a 289 head are. The best I've ran is a 15.4 at 88 mph. However, I was ahead of an '01 Cobra for the first 300 ft. I don't think I have enough gears in my transmission, or enough rear gear.so are the comp cams extreme energy flat tappet camshaft really work for you then! how much did both of them cost u!