Having just purchased a brand new SCAG 48" ZTR, I was amazed at the fact that the largest motor was a KAW 21 HP. After watching way to many episodes of "Home Improvement" , I just want more power !! The CID on these motors is the same, so how do you mod these engines to spec out to the higher HP ratings ? Any insite or help is appreciated, as I am sure there is someone out there that sells high performance parts.