This double-roller timing-chain set contains an adjustable, nine-keyway nitrated crankshaft sprocket; a double-row chain; a nitrated camshaft sprocket; two oil-pump-spacer plates; detailed instructions. Enhanced Strength & Accuracy Timing Adjustments (Advaned or Retard) up to 8 Degrees Includes Hardware *This timing set is designed with a 4X cam signal which is compatible with a 58X crank reluctor!