From my 4 stroke motorcycle racing days...smoothing the radii in the intake and exhaust manifolds and heads makes for a smoother mixture flow but may or may not change performance. What will help however is TUNING. Unless one could experiment with different length headers there might not be any performance gain available. As we've found out however,
the Moki radials don't need MORE performance. Out of the box they'll pull rediculously pitched props. Mitch