[ChevyBiker]

I have a GM engine...the stamping on the Transmission end is,
top left "corner" GM 3970010 and in the next "bay" is 11.
Pretty sure this isn't a "south of the border" block as no Hecho En Mexico stamping. I was told this is a mid-70's block....true or false?
Thanks From VEGAS BAYBEEE

[DoubleVision]

3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4

As you can see this was a rather common casting number. To know the year it was made there`s 2 ways. If the block hasn`t been decked, then a suffix code will be stamped on the deck of the passengers side of the block. A example of it is TCS. With your suffix code we can look up what it was used in and what years. Another way to tell is the date code that is on the bellhousing not too far up from the casting numbers, it looks like this example: E 5 8
The E indicates the month, E= May
The 5 indicates the date 5= 5th of may
The 8 indicates the year 8= 1978.

[ChevyBiker]

Thx for the reply....as you know...the "GM" numbers are in the 45 degree corner...in the next "bay" up there is the number 11....is this of any significance? There are no other numbers on the area where the tranny bolts up.

[Deuce]

Look on the front pad ... ( see above photo )
Where the Engine ID number/V.I.N. code is stamped
The last letters can tell you what the engine came installed in from the factory and its HP rating.

[ChevyBiker]

WOW! Your a BIG help...THANKS!
On the front pad,(below the "alternator") is stamped,
K0119TBF and directly below in smaller stamping, C91149897
Can you translate this for me?

[HalfOunce]

Originally Posted by ChevyBiker

WOW! Your a BIG help...THANKS!
On the front pad,(below the "alternator") is stamped,
K0119TBF and directly below in smaller stamping, C91149897
Can you translate this for me?

K=St. Catherines, Ontario 01= Jan 19= day TBF= suffix used for 1970 rated at 255HP and 1979 rated at 165HP trucks.
with that said you would need to check the casting date right behind the distributor hole to find out when it was cast to be sure if its a 1970 or a 1979