The CR500 project is what happened to the 86 250r frame. Thats why i have the extra motor to play with. A buddy of mine is putting his 92 Cr500 motor in it. It does sound like mybe something i don't want to tackle. My 416 runs good with the HRC cam and slip on pipe. Just got a Edelbrock carb so i will see what that does. Should help. I just though i would ask to see if it wold be a easy change. Thanks for all your help.