The rocker hits the base before proper seating. Might work with other brands. Use Comp Cams 4542-16 Magnum Rocker Stud Set for Harland Sharp. Says it’s for Olds and Dodge, but has the right thread patterns for Ford bolt down rockers. Along with Comp Cams 4842-8 Flat 1 Piece Guide Plates. Working now on an 80 Ford 4.9 using an 85 cylinder head designed for bolt down rockers. Other differences are valve cover bolt size and thermostat outlet.