The higher the better that way if the chain comes off it don't hit the head. I need to strip off the air breather,gas tank,exhaust so i can try and stuff it up high enough to get some clearance ideas. I think 1 inch or so would work just figured someone on here would of already had a solution or a mounting plate that they sold so i also could get a better sprocket alignment and chain adjustment when mounted since the motor is a pig with factory parts. the 3.5 clinton that i had on it would not align properly either.