They reccomend using the 063 pipe. Are the RN 063 And the OFNA 063 basically the same thing? becuase the OFNas one is alot cheeper, and the reason RB reccomended there own pipe is so they can make more money. Thats a bottom end pipe, and iv heard form some that they work wel with top-end pipes. What should i listen too? I wanna hear from people who actually own the engine. Its generally classified as a mid- Top end engine, so running it on a Low-end pipe like the 063 would make sense, but i wanna be sure before i sepnd my money., or should i get the 053 to help out botrh the bottom and the mid range?