The same Powerglide advantage (oil-fed axle, billet steel body, precision fit hydraulics), but now incorporates a Steady Roll bronze bushing in place of the needle bearing roller. These tappets have undergone extensive development to increase load, lubrication, hydraulic and life capacities. Billet body. Increased roller width. Roller perpendicularity held to .0002". Hand-honed hydraulic unit cavity. Dynamic load capacities increased over 30%. Lubrication capacities for hydraulic unit and valve train (top end) increased 10%. Lubrication capacities for the roller, cams and cam bearings have increased 100% for increased cooling. Made in the U.S.A..