Small and big block typical facts

Bore & Stroke Chart
Small Block Engine
EngineYearsBore
Diameter
StrokeRod LengthMain Bearing
Diameter
Rod Bearing
Diameter
Main CapsJournal SizeRear Main
Type
Notes
2621975-763.6713.1005.7002.4502.1002-boltMedium2 PC
2651955-563.7503.0005.7002.3002.1002-boltSmall2 PC
2651994-963.7363.0005.7002.4502.1002-boltMedium1 PCCaprice only
2671979-813.5003.4805.7002.4502.1002-boltMedium2 PC
2831957-973.8753.0005.7002.3002.0002-boltSmall2 PC
30219674.0003.0005.7002.3002.0002-boltSmall2 PC
3021968-694.0003.0005.7002.4502.1004-boltMedium2 PC
3051986-973.7363.4805.7002.4502.1002-boltMedium1 PC
3051976-863.7363.4805.7002.4502.1002-boltMedium2 PC
3071968-733.8753.2505.7002.4502.1002-boltMedium2 PC
3271968-694.0003.2505.7002.4502.1002-boltMedium2 PC
3501967-854.0003.4805.7002.4502.1002/4-boltMedium2 PC
3501986-014.0003.4805.7002.4502.1002/4-boltMedium1 PC
3501989-953.9003.6605.7402.4502.1004-boltMedium“LT5” in ZR1 Corvette 32 Valve DOHC
4001970-724.1253.7505.5652.6502.1004-boltLarge2 PC
4001973-804.1253.7505.5652.6502.1002-boltLarge2 PC
Big Block Engine
EngineYearsBore
Diameter
StrokeRod LengthMain Bearing
Diameter
Rod Bearing
Diameter
Main CapsJournal SizeNotes
366T1968-903.9353.7606.1352.7502.2004-boltStandard2 PCTall Deck Truck, small bore
3961965-694.0963.7606.1352.7502.2002/4-boltStandard2 PC
4021970-724.1253.7606.1352.7502.2002/4-boltStandard2 PC
4271966-694.2503.7606.1352.7502.2002/4-boltStandard2 PC
427T1968-854.2503.7606.1352.7502.2004-boltStandard2 PCTall Deck Truck
4541970-904.2504.0006.1352.7502.2002/4-boltStandard2 PC
4541991-19954.2504.0006.1352.7502.2004-boltStandard1 PCGen V
4541996-up4.2504.0006.1352.7502.2004-boltStandard1 PCGen VI, revised coolant passages
5021991-19954.4464.0006.1352.7502.2004-boltStandard1 PCGen V
5021996-up4.4464.0006.1352.7502.2004-boltStandard1 PCGen VI, revised coolant passages