Butler Pontiac Factory Crankshaft, 4.000" Stroke, 3.25" Main, 421/428/455 Blocks, 2.250" Pontiac RJ, Turned and Blueprinted

• Cleaned
• Shot Peened
• Checked for cracks and Inspected
• Turned no more than .020/.020
• We will confirm undersize once order is placed for proper bearing selection

We start with stock Pontiac crankshaft cores that have had no spun bearings or other damage. We send these cranks out to Lunati, one of the oldest and best crankshaft machining facilities in the US. The cranks are checked for cracks, shot peened to reduce stress, turned using state-of-the-art technology that ensures total crankshaft integrity and the ultimate in durability. The cranks are then blueprinted with the specifications to ensure they are within the tolerances that we expect for a Butler quality crankshaft.