Developed exclusively for Zodiac by TP Developments and made from the best alloy steel available today. These tappets are precision machined, then heat treated and finally ground to less than .0002" total readings at a 16 finish. They are called "Fat Axle" because they have increased roll strength and will not deform, even when used with extreme high lift cams. These extremely competitive priced tappets include the hydraulic unit and are the best tappets money can buy. Fits Panhead 1953-1964 and Shovelhead 1965-1984 with adjustable pushrods with 1/4" lower ball heads. Tappets have the stock .731" diameter and sold each. Note: The oversized "Fat Axle" roller axles may require a small modification in some stock tappet blocks. Alternatively order ZPN 131182 or 131183.