61FX
-----Or get a Performance Plus tuned muffler! You will pick up 500 -
1500 RPM, depending on the prop you are turning, I can guarantee it! Mine will turn a Scimitar 12-6 at 14k and an APC 11-7 at 15500! This on Wildcat Plus 15%. In the air it sounds like it picks up quite a few more revs.