The 053 wont let the engine rev to its full rpm range, and IF it does the pipe will try to stop it from doing so. The 3 port race has enough bottum end that the 053 is not needed on it. The 0801 or 086 is the recommended pipe because the engine has ample low to mid range, the pipe will help it to scream all the way through the power band. The 2047 or 053 will pretty much hinder the full potential of the mill. But like I said before if you will never have the engine on a track with a straight away longer than say 100 ft you can use the 2047-053 if you want, but I would use the 0801-086 no question. I hope that answers your questions.