The BTR Forged Crankshaft is a 4340 forged steel crankshaft built for GM LS-Series engines, machined to a 4.000 in stroke with an internally balanced counterweight design and a 58X reluctor wheel installed. It is core-hardened using a nitride process for improved strength, bearing life, and size tolerances held to +/-.0002", and uses a 1-piece rear seal.
- Part Number: BTRCRA4000F158
- Material: Forged 4340 steel, nitride core-hardened
- Stroke: 4.000 in
- Balance: Internal
- Reluctor Wheel: 58X, installed
- Rod Journal Diameter: 2.100 in, with .125 in radius on rod and main journals
- Oiling: Chamfered oil holes for improved oiling
- Counterweights: Chamfered and radiused leading edge
- Snout/Flange: Standard wet sump snout with 6-bolt rear flange, compatible with factory and many aftermarket balancers, flywheels, and flexplates
- Seal: 1-piece rear seal design
- Application: GM LS-Series engines
- Quantity: Each
- Install Note: Requires an OEM-style, one-piece crank gear
FAQ
What stroke and reluctor does the BTRCRA4000F158 crankshaft have?
This crankshaft is machined to a 4.000 in stroke and comes with a 58X reluctor wheel already installed.
Is this crankshaft internally or externally balanced?
It is an internally balanced crankshaft with a 1-piece rear seal, built for GM LS-Series engines.
What size crank gear does this crankshaft need?
The BTRCRA4000F158 requires an OEM-style, one-piece crank gear for installation.

