Originally Posted by thejudge

Hi Neal, Ive just bought an unused Clocked Plus 4 21-4BTT from a racer here in Aus. I'm going to use it in my mbx6r (I know I should update it, but it's dialled). I know that 9886 and 41001 is the best combo for the engine but I'm going to need a pipe that's on the ifmar homologation list. What's the next best combo to use?
I have the 41029 short manifold as it has the tighter bend suiting the mbx6r and also a 9901 pipe, how will this work?
I believe these engines are shimmed to run 30%, how ever I'm thinking of running 25%, will I need to re shim the engine?