HYDRAULIC : Choppy idle, increased compression advised. Needs 2500 stall and lower gear, use headers.Lifter Type: Hydraulic LifterEngine Family: Pontiac 265-455 c.i. 8 cyl. 1955-1981SpecificationsRPM Range: 2000 to 6000Valve Timing: 0.006Lobe Separation: 110°Intake Centerline: 106°Vehicle Fitments:...