Technical What is this?

I have a motor that I pulled out of a 73 GMC I'm wondering what it is because it looks like it has triple camel hump heads on it. somebody please help me!!! I will attach a picture of the heads and engine stamp.

 

that is not an SBC

 

Then what exactly is it?

 

Sbc...... small block chevy.

 

it is not a small block chevy. looks like pontiac blue/green. can you post a whole picture?

 

How about a pic of the complete engine?
Not SBC

 

Motor

 

Side

 

Head

 

Looks like an Olds engine. 350-455.

 

Oldsmobile - ‘77-‘80 350 according to the head casting

 

Oldsmobile

Sent from my Moto G Play using The H.A.M.B. mobile app

 

First impression says Olds.

 

Head

 

Can you please tell me how you read the head casting numbers? I want to learn.

 

554716

This website is a good source of information
http://www.442.com/oldsfaq/ofhed.htm

 

Spark plugs above the exhaust manifold = Not a Sbc.

 

Thank you very much

 

Modern small block heads are identified by a single number and usually an accompanying letter like this one you posted, 7A. That and 5A are the most common. For big blocks there will be a single letter such as C, D, E, F (all desirable) or J (smog head, tiny exh port)

 

From the site Anderson referenced
3A '77 - '80 350 75 554716 1/2" bolt holes.

 

you lucked out. back then, lots of people bought oldses and got sbc's in 'em. gm wound up paying everybody!

 

Are you sure the truck was a 73? A lot of late 70s diesel trucks had olds gas motors put in them after the 350 diesels expired.