The Fox .60 won the MAN shoot out last winter, they have a .74 version also, Tower came in second. The Tower probably suffers from some QA problems, but the FOX has a carb design flaw but is fixable. If Fox has come out with the new twin needle version I would try that. Engines not in the shoot out I would consider before most of the engines that were in the shoot out are the Webra .60, HP .60, and K&B Twister .60.