Help identify engine in 1983 Jimmy

[XRO]

Just purchased a 1983 Jimmy at an auction and have zero history on it. I ran the vin number confirmed this vehicle came from the factory as a 305, but wanted to verify if that was the current engine. Just checked the casting number on the block and it is 3970010. Quick google search indicates this could be an older 302, 327 or 350 ( 2 or 4 ). Any thoughts on on how else to verify exactly what I have with out tearing into it?
Thanks much

3970010 302 4 69 290 Z-28 Camaro 3970010 327 2 69
Truck 3970010 350 2 or 4 69-80
Truck

 

[1leg]

302/327 blocks from 1969 are pretty rare to come by, I would give it about a 2% chance that it would be anything other then 1 of the millions of 350 block made.

http://www.nastyz28.com/chevy-engine-code-stampings.php

 

[XRO]

It was difficult to make out, but on the milled surface behind the alternator it looks like 1041BA is stamped - although my searches are telling me I'm missing digits here? Also, on the bottom of the block is 371-338.

 

[dyeager535]

Agree on "BA", sure it's not "EA"? That would be a 327.

 

[4X4HIGH]

Casting 3970010 is definately a 350.