Well I think I'm leaning towards either the N21BF or the B5 now. I think it's more towards the B5. Would the dynamite 053 or 086 be a good pipe for either one of these engines or should I get a JR pipe. Don't know a whole lot about pipes yet. I'm sure I will have to figure out which one I like. The only one that I have run is the 053 on the mach 2 .21