I am pretty sure I wont be porting my banshee. I heard the cpis work great on ported motors thats why I kinda want Toomeys instead. I just cant decide on the T5s or T6s. Toomey said that the T6s were specifically designed for a stock bike and if I put a cool head on, he said it might mess with the way the power band hits and maybe even the performance even with the correct domes. Thats why I asked.