Our Hydraulic Lifter Units are crafted in Japan and are made of the highest quality materials. If you are rebuilding an Antique Harley Davidson Panhead Or Shovelhead FL FLH than these are great units to use. You may also need these Hydraulic Lifters if you are using solid rods in your engine/motor. These fit 1953-1984 Harley Panhead & Shovelhead.