Toomey TR-6 well all thought most of the posting in these forums have really been insufficient I do appreciate the fact they do exist. I was unaware up till know that if you had a stock motor that you should go with the TR-6 if you plan not to change exhaust porting, compression, or timing and such. These words straight from Toomey themselves they say due to the length of the head pipe I believe these work best with stock motor. Now if you decide to make upgrades as listed above your choice of pipe should be the Toomey T-5