AMS Racing 9 Keyway Double Roller Billet Steel Timing Chain Set for Small Block Chevrolet 305 350 400 EnginesOur billet steel true roller timing sets have rugged double row, true roller chains teamed up with billet steel crank and cam sprockets. The crank sprockets have multiple keyways, which allow you to modify your cam timing. Note: This will not fit OEM roller camshafts Timing Chain Style: Double roller Camshaft Gear Attachment: 3 bolt Maximum Advance Retard at Camshaft: 4 degree Maximum Advance Retard at Crankshaft: 8 degree Thrust Bearing Included: Yes