I recommend A GO TECH .21 5 port race with the GO 0801 pipe or the Dynamite 086. Just as much if not more powerful than the V-spec and like $100 cheaper. And if taken care of well could get the same if not more gallons of fuel through. This motor has amazing low end power and with the recommended pipes will pull hard for ever. And with the $100 you save you can send the engine to your local modifier and have an even more powerful mill.