Roller or flat tappet cam one-piece rear seal III, 6.0L, truckĬrossbolted block, Gen.III, 6.0L, aluminum, LS2Ĭrossbolted block, Gen.III, 5.3L, aluminum, SSR truckĬrossbolted cast iron, Gen.III, 6.0L, truck Vortec truck, Gen.I crate motors and ZZ4, roller cam, one piece rear sealĬrossbolted block, Gen.III, LS1, aluminumĬrossbolted cast iron Gen. Vortec truck, roller cam, one-piece rear seal L99, Gen.II, 4.3 Liter V-8, Caprice, reverse flow cooling Goodwrench crate motor, 2-piece rear seal, 'Hecho en Mexico'īowtie Aluminum 4.125 bore, 2.65 main journalsīowtie Aluminum 4.125 bore 2.65 main journals Target Master/Goodwrench crate motor, 2-piece rear Goodwrench crate motor 2-piece rear seal 'Hecho en Mexico'Īluminum, Pontiac Super Duty version of Gen.I SBC, 4.00 bore,ģ50 mains, 2-piece rear seal, splayed caps, GTP race blockīowtie, 3.75-4.30 bores, 1 or 2-piece rear sealīowtie, 4.00-4.155 bores, 1 or 2-piece rear seal Was also used for some CE replacement blocksĬhevy II recessed oil filter boss, Used for some Chevy II CE replacement blocks Some replacement blocks had 2-bolt main caps Some Canadian assembled heavy duty truck blocks have 4-bolt main caps Some Canadian assembled heavy duty blocks have 4-bolt main caps.īowtie, Aluminum, siamesed, straight nodular iron main caps 2-piece seal, 4.00-4.150 bores, 2.45 main journalsīowtie, Aluminum, billet main caps,3.398 bore with sleeves, 2 piece rear sealīowtie Aluminum nodular iron splayed caps wet sump 4.00 bore On the side of some later blocks the last three digits of the block casting number are cast into the block, but these are difficult to see when the engine is in a vehicle. You may see a “5.0” (305) or “5.7” (350) cast on the rear ledge of a small block or a “7.4” on the side of a big block 454. Also some of the later blocks have the size of the motor shown in liters. There are sometimes other individual letters found on blocks like “GM” or “CFD” for the Central Foundry Division, but they are not part of the block casting number. The block casting numbers do not have any letters in them. The number itself can have 6, 7 or 8 numeral digits. Some of the later model blocks have the casting number on the passenger side of this ledge. This ledge is below the deck of the block and the ledge forms the mating surface between the block and the transmission bell housing.

The block casting number on small block and big block Chevy V-8 motors is located on a ledge found at the rear of the block, most often on the driver’s side.

Sbc numbers on front of block