Wildcard

ok. i found a olds v8 in a 80s GMC truck at a local scrap yard. it doesnt say 5.0 or 5.7. i didnt get the block number. is there any other way to tell what size the motor is?

Octania

Yes, get the block ID

Or, the heads' ID will probably do, to begin with. On your lower left as yo uview the engine from the side.

Eightupman

Casting number on the shelf next to the oil fill tube above the water pump will ID the size of the block. Since the heads are interchangeable (for the most part) it's not best to count on them to ID a motor.

The early 80's trucks that came with a diesel were the Olds version. So when the motor gave up the ghost, the logical swap for most was an Olds gas motor. 403s were plentiful back then... Wonder if that truck has the HydroBoost braking system...

John

Wildcard

im gonna get the block number tomorrow and run it after work. it didnt say the motor size were the casting number was. thats what i looked for. i do know its a gas motor.

joe_padavano

Only the late 1970s and up motors have a size as part of the casting numbers. Earlier blocks just have a casting number that can be mapped to the displacement.

Wildcard

ok. the block casting number is 557751-2B and its in a 76 GMC full size pickup truck. does anyone know what displacement the motor is or how i can find out?

Wildcard

ok. never mind. i ran the numbers. it cam back as GM's most worthless v8. a 260. i defently dont want that motor.

oldsman72

Just did a web search... It's a 77-82 olds 4.3l v8 according to "engineguy".

Eightupman

Jeeze that thing must have been an absolute JOY to drive...

John

Wildcard

power of a 4cyl and the MPG of a v8

olds 307 and 403

Man, even the diesel would have been faster plus twice the mileage. The worst Olds V8 ever. At least the early ones were solid main and had slightly less pathetic heads. There was no upside to the later window web dogs. Similar to the 267 sbc, they were give away motors.