is it a 74 or 80 inch shovelhead cylinder?

One of the most common questions is “Do I have a 74 or 80 inch shovelhead cylinder?” Shovelhead cylinders are basically the same on the outside dimensions. The bore of the cylinders is however different. Standard size 74″ cylinders are 3 7/16″ or, 3.4380″ and 80″ cylinders are 3 1/2″ or, 3.498″ . Visually it … Read more

S&S Piston Clearance

I had a set of S&S 92-2500F cast pistons to fit to cylinders and could not find any instructions on S&S’s website, so I looked in my papers and found a instruction sheet. Figured I’d post it up here because getting answers from them isn’t reliable. As long as I’ve been dealing with S&S I … Read more