Product Summary

4.125" Stroke, Forged 4340 Steel Crankshaft Material

  • Suitable for road race, marine, circle track, and street/strip builds
  • Made from 4340 steel with deep nitriding for strength and wear resistance
  • Counterweighted for better bearing load distribution, large journal radii, gun-drilled mains, and lightened rod journals
  • Available with LS2/LS7 (58-tooth) or LS1/LS6 style twin timing wheels
  • Cranks can be rough or finish balanced to your bob weight, with an option for extended length posts for dry sump LS7 builds
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Key Specs

Stroke4.125"
Crankshaft MaterialForged 4340 Steel
Main Journal Diameter2.559"
Rod Journal Diameter2.100"
Rear Main Seal Style1-piece
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Callies APU-31Q-CS Details

Compstar LSX crankshafts are designed for high-performance applications, offering a wide range of configurations for road race, marine, circle track, and street/strip builds. Made from durable 4340 steel with deep nitriding, these cranks feature counterweights for improved bearing load distribution, large journal radii, gun-drilled mains, and lightened rod journals, making them ideal for high boost and high RPM engines. They are available with either LS2/LS7 or LS1/LS6 timing wheels and can be customized for dry sump LS7 engines. Cranks are sold either rough balanced or finish balanced to your specifications.

  • Suitable for road race, marine, circle track, and street/strip builds
  • Made from 4340 steel with deep nitriding for strength and wear resistance
  • Counterweighted for better bearing load distribution, large journal radii, gun-drilled mains, and lightened rod journals
  • Available with LS2/LS7 (58-tooth) or LS1/LS6 style twin timing wheels
  • Cranks can be rough or finish balanced to your bob weight, with an option for extended length posts for dry sump LS7 builds

CARB Warning

For race/ off road use or for use on pre-1966 vehicles.

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

Callies APU-31Q-CS Specifications

KEY SPECS
MFG. Part #APU-31Q-CS
BrandCallies
Stroke4.125"
Crankshaft MaterialForged 4340 Steel
Main Journal Diameter2.559"
Rod Journal Diameter2.100"
Rear Main Seal Style1-piece
Engine BalanceInternal
GENERAL
Narrowed BearingYes
Main Bearings IncludedYes
Connecting Rod Bearings IncludedYes
Snout TypeStandard
Sold in QuantityEach

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