Engine found in swamp...what kind is it?

I bought a house up here in Maine with 4 acres last year and today I took my first walk through the woods (more a swamp really). I found the door to an old car which looks to me by the handles to be GM, may 40's or early 50's. I also found an inline engine, with a 1-bbl. intake...see photos. I could not find a number on the fuel pump but it was hard to see. Appears to be probably a straight six with the intake on the passenger side. The intake runners were buried so I couldn't count 'em.

Any ideas?

Couldn't you have, at least, brushed some of the leaves and twigs away???

Had nothing with me except my camera. This thing is embedded...keep in mind I'm standing in a swamp and the whole engine is wrapped in roots. However I just hiked out there and was able to clean it a little better. Looking at the exhaust/intake arrangement, this thing looks old to me. The heat riser flapper weight has a pretty distinctive "Pac-man" shape to it.

Narrowed it down to possibly an old Pontiac flatline...single barrel would be 1933-1940. An illustration of a 1937 Pontiac engine is extremely close, but the intake is slightly different. This engine I found has the vacuum port on the extreme left of the intake manifold and no "dip".

Remove the fuel pump and take a picture of it from the side and post it, also there my be a number on the fuel pump flange that would help.

Marv.