Help identifie this engine, early corvette?
 

Block casting #3970010
Suffix casting on right front of block#VO482400, No letters or partial vin.
From LEFT to right, overbellhousing on block. In the first valley there is the block casting, then a big time clock, then #0298.
This engine has a two barrell carb and a metal cast intake.
And the peg on the block where the suffix code is stamped is square peg looking, unlike the #3970010 original block I have in my 72 chevelle that has a square block with long edges on both sides. see photo's.

And one other thing the chevelle engine was orange from the factory and the other unidentified block was blue from the factory. What do the different colors mean?

your engine
 

http://www.nastyz28.com/sbchevy/sblock.php

1968 3970010 327 - - 2 A
1969-79 3970010 350 185-370 hp 2 or 4 main cap, truck, Vette

The V identifies it as a Flint built engine. Without a partial VIN, likely a crate engine.
The orange was when a Chevy was a Chevy, a Pontiac was a Pontiac, a Olds was a Olds, etc. Each division had their own color. They went with the blue when the engines became "corporate".

The "CMJ" suffix is:

Code Year CID Vehicle HP RPO Trans Carb Comments
CMJ '75 350 Impala 145 L-65 TH 350 2-Brl A.I.R.
CMJ '75 350 Chevelle 145 L-65 TH 350 2-Brl A.I.R.
CMJ 80 305 Impala 155 LG-4 TH 350 4-Brl
CMJ 91 350 Cadillac 185 L-05 700R TBI

Combined w/the casting number 3970010, which is:

350...69-80...2 or 4,

this is a 1975 350 from either an Impala or Chevelle.

http://www.hotrodders.com/gallery/data/500/SUFFIX.jpg

I think you decoded the block in the Chevelle.
"Suffix casting on right front of block#VO482400, No letters or partial vin."

i've been trying to figure out the same motor. So far I've figured out that its a
75 - 79 350. Dont know if its 2 or 4 bolt. Still gotta drop the pan and find out. And from what I can tell it was a crate motor.
hope that helps