Hi, I just rebuild a 425 engine out of my 1963 Riv. Neither my original shop/chassis manual nor the electronical one on CD has the specs (clearences, fits, adjustments..) - only the stuff for a 401 are described. in the web the best I found is the data of a 1966 425 engine. Does anyone have a better idea? Or have a shop manual including the 425? Thx Robert