This double-roller timing-chain set is a perfect complement to our high-performance camshafts and other LS1/LS6 engine components. It offers greatly enhanced strength and accuracy compared with the stock piece, and even allows for timing adjustments (advance or retard) of up to 8 degrees. The set contains an adjustable, nine-keyway nitrated crankshaft sprocket, a double-row chain, a nitrated camshaft sprocket, two oil-pump-spacer plates, detailed instructions, and all necessary installation hardware. Compatible with all 1997-03 "Gen III" engines (LS1/LS6, 4.8L, 5.3L, 6.0L).