To all, When you use a higher lift cam (like a Purple Cam), the cylinders look for more air/fuel mixture. When it is short on that, the engine will be 'flat' on the take-off. You will need to add a larger CFM carb. ie, if you have a 600cfm, you may need a 750cfm, etc. Crash 300-K convert [Non-text portions of this message have been removed]