If you plan on keeping your motor in the stock form, I say 100% T-6's.. But, they do not react well to porting and later modifications. If you plan on porting down the road, I would go with a different pipe, rockets, cpi's, T-5"s. Toomey themselves agree that the T-6 Pipe is great for a stock motor. And them seem to stress the STOCK part of it. Ive read alot of people not liking to T-6's.