For Chevy SBC 350 1.5 Ratio 7/16" Aluminum Stud Mount Roller Rocker Arm Set w/Poly Locks Fit most all small block Chevy stock and aftermarket 23 degree cylinder heads. Aluminum ROLLER ROCKER ARMS Kit For Chevy SB 1.5" 7/16, 16 CNC Aluminum Arms With Polylock Nut Creates less friction, allows more accurate valve adjustment and has extreme rigidity Lightweight with integral push rod seat Not self aligning