Help Identifying Block

[1970 CST]

My truck which is supposed to have a 350 currently has an older 305 in it. While scanning FB market Place I saw an ad for a 350 engine out of a 1970 Chevy pick-up. I picked up the motor, less an intake for $250. Looking over everything I am confused by the numbers.
Casting - 3970010
Center of Block below intake - M (in a square) followed by 6
R/F of Block - K11 05 TBB

The question I have is the TBB can either be a 1970 C10-3500 or a 1979 C10-2500?
On the right side of the block there is the following.
A 1
D < N
Any help would be appreciated.

[basketcase]

3970010....302.....69....4 bolt...Z-28 Camaro (Not likely what you have)
3970010....327.....69....2 bolt ...Trucks and industrial
3970010....350...69-80...2 or 4 bolt car or truck (most likely)
You need to post the casting number to determine the age of the block. It is on the bellhousing flange in the same position as the casting number but on the passenger side.

[1320NUT]

3970010
69-79
302/350
car & Truck 2 & 4-Bolt Most common

[1970 CST]

This is the only thing on the right side back of the block. Other than this I posted the casing numbers on the right side of the block.

[1320NUT]

what is the stamping, on the passenger side, on the front of the block, above water pump port? part of it, will be the vin number, and the other will tell more about the block?

[1970 CST]

K 11 05 TBB According to the charts I’ve seen it could be a 1970 or a 1979 350 block. Not sure how to determine which?

[1320NUT]

snap a picture of the pad above the water pump if its a short pad its a late block if its a long pad its a early block?

[1970 CST]

Attached

[1320NUT]

Early block for sure let me see if I can do something with those stampings

[1320NUT]

TBB
1970 350 cv/fd cab, m/t 3sp 255hp 4bbl C-10 to 3500

St. Catherines, Ontario was the foundry. (McKinnon Industries Canada)

[1970 CST]

Thank you, I couldn’t figure out how to differentiate between the 1970 and 1979. Super glad it’s a 70. My CST currently has a 67-68 305 in it. I think this one will be a nice change when I’m finished with it.

[1320NUT]

Have you torn down the Facebook engine? look at the crankshaft number it will tell you if its a 350 or not I believe the last three numbers are 442?Early Chevrolet 350 crankshafts can have casting numbers such as 3932442

[Palf70Step]

Originally Posted by 1970 CST

T..... My CST currently has a 67-68 305 in it...............

305 V8 wasn't available till 1976. More than likely you have a 307 (68-73) or 283 (67 and older). I always had good luck with the 307s. I think visually the 283 had the oil fill tube in the intake and the 307 use valve cover oil fill. That's if they are stock. Good luck with new engine. The 350 should add a bit of zip to it.

[MJN]

Is it just my eyes or do you have fine thread bolts threaded into the bellhousing bolt holes?

[Steeveedee]

I don't see any black paint on this. When did GM start painting the engines black at the factory?

[1320NUT]

Starting painting engines black in 1988 when throttle body fuel injection came out

[MJN]

Originally Posted by Steeveedee

I don't see any black paint on this. When did GM start painting the engines black at the factory?

Black painted engines started in the late 80's (1987ish)

[Steeveedee]

OK, so I was hoping to eliminate the newer year by color. Didn't work.

[1970 CST]

Originally Posted by MJN

Is it just my eyes or do you have fine thread bolts threaded into the bellhousing bolt holes?

3/8 course, you're seeing the 2" adapters I made out of 3/8 black pipe to get clearance from the engine stand.

[1970 CST]

Originally Posted by Palf70Step

305 V8 wasn't available till 1976. More than likely you have a 307 (68-73) or 283 (67 and older). I always had good luck with the 307s. I think visually the 283 had the oil fill tube in the intake and the 307 use valve cover oil fill. That's if they are stock. Good luck with new engine. The 350 should add a bit of zip to it.

My mistake, the casting number on the engine that is currently in the truck is for a 307, although the intake and Valve covers are from a 327? Haven't looked at the head casting numbers. Frankenstein motor.

[1970 CST]

Originally Posted by 1320NUT

Have you torn down the Facebook engine? look at the crankshaft number it will tell you if its a 350 or not I believe the last three numbers are 442?Early Chevrolet 350 crankshafts can have casting numbers such as 3932442

Might start tear down tonight, see what I find.

[1970cstblazer]

Originally Posted by MJN

Black painted engines started in the late 80's (1987ish)

The engines in both my 1984 K/5 Blazer and Caprice with 305 were black.

[67 twins]

Originally Posted by 1320NUT

Starting painting engines black in 1988 when throttle body fuel injection came out

TBI came out in 87 not 88