Engine ID

[Kilian]

Hello. My previous question about what exhaust manifolds to use on the 350 in my 83 GMC C2500 got me thinking that I should check to see if someone swapped engines before I acquired the truck. After cleaning off the grease I've come up with these numbers:

Engine Casting Number: 3970010
Engine ID Numbers: 15S122463, V0108CMJ

Using a decoder on nastyZ28.com, it would appear that the ID numbers indicate:

350 Engine from 1975, Saginaw plant, made on January 8, used with T400 Police transmission?

Is this correct?

 

[bucket]

Sounds correct. I think that block number was '79 and older?

 

[HotRodPC]

Pretty sure the V designates Flint, Mi engine plant where most small blocks were made in that era, and the big blocks were mostly made in Tonawanda, NY. But you're correct on the 0108 being Jan 8th. Without looking up the suffix code, I won't swear to the rest about the year and police blah blah.

The 3970010 is one of the most common 350 block cast #'s and comes in both 2 and 4 bolt. It was also used for the Large Journal 327. It was actually a 327 block to begin with in 68 then got stroked to a 350 and took off. The early 327's from 62-67 were considered the small journal 327's with the same size journals as 265 and 283 which all small journal engines had forged cranks. Not most or some, but all small journal engines were forged cranks.
So there's that tidbit of history for just because.