As with many, need help identifying SBC

[Habanero]

The truck originally had a straight 6, 3 on the tree. Noe has a small block v8 and turbo 400 auto. The engine was installed so far back in the compartment that the VIN can not be read. The front passenger side stamp has 10D187707 and Serial number of T0512GNR. Have no had much luck other than Plant name, day and month. No idea what GNR is in terms of vehicle.

Any help would be appreciated.

 

[63Half-ton461]

Hi , remove the left side valve cover and take note of the casting number on the cylinder head , let me know what it is and i will tell u what engine you have,

 

[Habanero]

I am not sure the heads are original to the engine I was told that the heads were very good ones. I will look and let you know.

Just to be sure, drivers side or passenger side?

Thanks!

 

[63Half-ton461]

Ether side will have casting numbers , i just suggested pass side as yur engine is set back and the brake booster might make it more of a bother and usually when i ask people for cylinder head casting numbers i never hear back.

 

[63Half-ton461]

Some blocks have the last 3 digits of the casting number somewhere on one of the sides of the block, so if u happen to be poking around under the front end have a look up at the block side an see if they cast any numbers up there.

 

[63Half-ton461]

Even if the heads were not original the casting numbers can still confirm whether u are looking at a 305 or a 350, i know more than a few 305's have been passed off as 350's (hell it happened to me on a s10 i bought once, lol) and in general people don't put 305 heads on 350 unless they are looking for huge compression (propane conversion perhaps) bump ....