Engine code or date code?

[steveimpala]

Question, my 1969 396 engine has the following stamp on the passenger side: 10 21 YS , is this a date code ?


Thanks !

[CAMAROBOY68SS]

the casting date is on the back of the block near the bellhousing flange on the passenger side and its cast into the block not stamped.

I think what your posting is the front pad code, YS comes up as a 69 Truck motor.

[steveimpala]

Thanks !

[MJN]

10 21 is the engine assembly date- October 21
YS suffix code is for a 1969 396 truck engine, 310hp, 4bbl carb, manual transmission
There should be a letter at the very beginning of the stamped code that will tell you the engine factory.
F- Flint, MI (1955-1966)
V- Flint, Mi (1967 and newer)
T- Tonowanda, NY
K- St. Catherine, Ontario
S-Saginaw, Mi
M- Mexico

The date cast into the block is the date when the block was cast and which shift it was cast on.

[steveimpala]

thanks !

['68OrangeSunshine]

Originally Posted by MJN

10 21 is the engine assembly date- October 21
YS suffix code is for a 1969 396 truck engine, 310hp, 4bbl carb, manual transmission
There should be a letter at the very beginning of the stamped code that will tell you the engine factory.
F- Flint, MI (1955-1966)
V- Flint, Mi (1967 and newer)
T- Tonowanda, NY
K- St. Catherine, Ontario
S-Saginaw, Mi
M- Mexico

The date cast into the block is the date when the block was cast and which shift it was cast on.

I don't think they stopped using F for Flint built engines in 1966, they just added a second production line to keep up with demand in 1967 = V.
I have 292 blocks from '67 and '68 that have F codes in the stamped dress numbers.

[MJN]

Originally Posted by '68OrangeSunshine

I don't think they stopped using F for Flint built engines in 1966, they just added a second production line to keep up with demand in 1967 = V.
I have 292 blocks from '67 and '68 that have F codes in the stamped dress numbers.

That came right from The Lime Book as my source.http://www.camaros.org/pdf/LimeBook.pdf

[MJN]

Then theres this chart from Inliners International, its not clear if the six cylinders remained F and the V8's changed to V. The Lime Book only covers V8's.
https://www.inliners.org/ubbthreads/...t&Number=66011

['68OrangeSunshine]

Originally Posted by MJN

Then theres this chart from Inliners International, its not clear if the six cylinders remained F and the V8's changed to V. The Lime Book only covers V8's.
https://www.inliners.org/ubbthreads/...t&Number=66011

I've never seen an L6 with a 'V' engine dress digit, but then I have not seen every L6 ever built. My three 292s were all built on the F Line. One a '63 Core, a '67 I ran from 1977 to 2002, and the OEM '68, that came in the truck when I bought it in 1973. I put it up in crates in 1977 and rebuilt it in 2005.

[1970cstblazer]

The Lime book is good, but some info is not 100 percent correct. For example, the engine code on my Blazer's 1970 350 4 speed is:

V0223TBC

V Flint

0223 February 23, 1970

TBC is listed in that book as a 1970 350/255BHP 4 barrel carb truck engine with a 3 speed manual trans.

[MJN]

Originally Posted by 1970cstblazer

The Lime book is good, but some info is not 100 percent correct. For example, the engine code on my Blazer's 1970 350 4 speed is:

V0223TBC

V Flint

0223 February 23, 1970

TBC is listed in that book as a 1970 350/255BHP 4 barrel carb truck engine with a 3 speed manual trans.

Continuing to go off topic from the OP's original question..
Looks like https://www.nastyz28.com/gm-chevy-co...s-suffix-6.php is incorrect as well then even though it shows it as MT, 3 spd.
If there are better sources for this information feel free to post it up. The GM book simply shows Manual transmission, does not specify 3 speed or 4 speed. http://www.gmpartswiki.com/getpage?pageid=21050

The GM P&A catalog does not specify the change from F to V or addition of V to the engine plant identifier. The things I've seen that is common among these sources (Lime Book and nastyZ28) is F is Flint (Motor) and V is Flint (Engine). Also, the Lime Book is only V-8's, no mention of 6 cylinders and I guess I didn't say that applied to 6's either. Its possible the 6's kept the F prefix, we all know there are many other nuances with these trucks that don't seem to follow logic or are well documented.

[54blackhornet]

Do you think the folks with 2024 pickups will be sleuthing like this in 50 years .