I am in the precess of rebuilding my old 98 670 with fresh crank and top end. I have two rotory valves, one stock and the other came with a parts motor i bought, its also a 98 670. If I line the edges up on both RV's and put the pin wheel on top there is aproximatly 7 degrees more or 3.5 deg per side. the larger RV is in better shape. can anyone tell me what its from/aftermarket? How to time it and what will happen if i put it in? thanks!