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
SBC Casting Numbers and Applications Casting 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 smallblock 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 bellhousing. The block casting number on smallblock 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.
