Zachary Riggs

I am very new to project cars as this is my first one, so please excuse any incorrect terminology or general newby-ness.

I bought a 1981 C10 that has a rebuilt 455 oldsmobile motor in it, my question is are there identifying numbers on the engine and if so whereare they/ how do I know what they mean. I would like to know what year and model the engine came out of for ease of purchasing parts.

Thanks in advance for any feedback.

Olds64

Zachary, there are casting numbers on the engine that will identify what year vehicle it came out of. Sorry I don't know which casting numbers they are, or how to decode them. As far as parts availability goes I don't know of any 455s that have different parts besides maybe cam, heads and pistons.

BTW, what heads does your 455 have? There should be a letter cast into the heads. If it is a J it is from a later "smog" motor. The most desirable for performance are C heads with the big valves. There are a lot of others too.

joe_padavano

There are casting numbers that will narrow down the year range. There is a VIN derivative stamp that will tell you the model year and depending on the serial number range and assembly plant you may be able to infer the original application. Unfortunately, there is nothing on the engine that will prove definitively what it originally came from. You don't even know if the block and heads were born together or if this is a frankenmotor built from parts. You also don't know if it is stock inside or not, so knowing the original application may not be particularly useful anyway. I assume this was formerly a diesel truck? Replacing the dead 350 Olds diesel with an Olds gas engine was not uncommon.

Zachary Riggs

Im pretty much in the dark as far as where any of it came from my grandma bought it and i guess doesnt remember anything the seller told her. I know it has a lot of work, after blowing a head gasket and doing that full repair i know its bored .60 over, has roller rockers, holley double pumper carb, mallory distributor, and a few other upgrades. Ill have to check on the "C" or "J" heads next time im by the truck. My next step is after market oil pressure and water temp guages since neither of mine are working.

Fun71

Below are pictures showing the locations of the VIN stamp and the head casting number.


P1010401-1.jpg

Head_ID.jpg

Olds64

Thanks for posting those pics Ken. A picture is worth a thousand words. Let us know what you have Zachary.

Zachary Riggs

So I found it thanks to those pictures Ken, super helpful. 39M600345 was stamped as well as C on the head. I did some googling, not sure how to decipher the numbers though

joe_padavano

3 = Oldsmobile Division
9 = 1969 model year
M = Lansing assembly plant
600345 = sequential build number of the car it was born in

Note that for the 1969 model year at the Lansing plan, Olds assigned serial numbers 100001 - 500000 to RWD cars and 500001-up to Toros, so this block came from a Toro. If the C heads are original to that block, they will have big valves.

hurst68olds

I believe Toronado started at 39M600001 for 1969

so, the engine started life in a very early (August 1968) '69 Toronado

Olds64

So Zachary, are you going to keep the 455 in the C10 or are you going to find an Oldsmobile that needs a transplant?

Zachary Riggs

game plan is to keep it, sell it all together once i get all the kinks worked out

Olds64

I hope you can make a few bucks. GLWS!