Getting ready to put the 70 LT-1 engine back in the '62 Corvette. I bought a cloyes true roller set and a Jeg's Alum timing cover. There seems to be a fit problem using a cam buttom (.640 length). My question is, the cam is the stock 70 LT-1 mechanical cam and lifters. Do I really need the cam button? If so, can I shave a little off the back to gain enough clearance to make it fit? how much clearance should it have.