I would heartily recommend the OS 32F. Works great with the stock carb, should go about 75-80 on 10% with an APC 9x6. I'm watching one on the bay right now that's about $11.00 with 3 days left. There's also a NIB one from the same person at about $33.00. As a plus, the same mounting pattern will fit the EVO 36, Irvine 36, ThunderTiger 36, OS 32SX and 35AX, Webra 32-36 and a host of others.