ApplicationCompatible for Pontiac Oldsmobile V8 350 389 400 421 455 Retro-Fit Hydraulic Roller LifterSpecification Lifter Link Bars Included: YES Lifter Outside Diameter (in): 0.8425 in Lifter Style: Hydraulic roller Link Bar: Vertical Quantity:Sold as a set of 8 pairs as shown Features- 100% brand new - High performance aftermarket products made in our own lifters factory with more than 10 years experience - A fast and affordable way to easily upgrade your car\'s appearance performance - CNC Machined for Maximum Accuracy - Forged, Heat Treated Chrome Alloy Steel Body for High Strength - Precision Machined and Heat Treated Internal ComponentsNotesRetro-fit for non-roller blocks. No instruction included; professional installation is suggested.