I Just bought a confirmed by build sheet 79 Z28, and the engine seems to be out of another GM car or truck.

Partial vin is C4J168316, Suffix looks to be VO422T2M, But the T could be a #1.

If it matters, the oil stick is on the drivers side and looks to be no provisions for one on the passenger side.
Block Casting is 3970010, Also has GM 23 on same side as block casting#.

C4J168316 VO422T2M

GM
23 3970010

I tried to do my homework on this one, but seems its beyond me. Any help is appreciated

Its from a 1974 Chevy Truck

C4J168316 is the con vin
C - Chevrolet Truck Division, car div is 1
4 - 1974 (1984 used letter E)
J - Janesville T&B Assembly
168316 - Production serial number, starts at 100001 so this is 68,316 truck built at Janesville, Wisconson Assmbly in 1974. Janesville still running today, big trucks, Suburbans/Yukon XL and Tahoe/Yukon

VO422T2M
V - Flint Engine Plant
04 - April 1974
22 - Day
T2M - The 2 is something else, until I know what all I can say is that its a 350 engine, probably 160 hp LS9. Nothing special with the 1974 truck engines. The were low compression gas pigs loaded down with ant-smog parts.

T woudl be right, all truck suffix start with a T, car with C.

The casting 3970010 was cast in the millions and used for over 10 yrs in every production Chevy vehicles in many different applications.

Hey thanks and i thought i was going crazy. Did'nt think it was some rare engine, just could'nt find out what it was.
thanks

if its a truck engine it should have 4 bolt mains so it has some redeeming qualitys

Not all truck engines are 4 bolt main bearing. HD truck engines are but what they used in PU's is not often considered Heavy Duty. These block were machined both ways.

The only sure way to know is to drop the pan and look.