There are no issues with powervalve or reedcage clearance. You will need to have the head machined for the new bore. The stock head gasket will not work, but the Cometic gasket has the proper diameter. It makes the motor a real grunter if done right (proper porting) As far as jetting, every motor wants something different. If you do no other mods, you may end up leaning down the main a tad.