Engine code or date code? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**steveimpala** · 03-19-2024, 12:29 PM

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

Thanks !

**CAMAROBOY68SS** · 03-19-2024, 12:53 PM

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** · 03-19-2024, 01:06 PM

Thanks !

**MJN** · 03-19-2024, 01:09 PM

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** · 03-20-2024, 04:43 AM

thanks !

**'68OrangeSunshine** · 03-20-2024, 06:58 PM

Quote:

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** · 03-20-2024, 07:36 PM

Quote:

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** · 03-20-2024, 08:19 PM

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

03-19-2024, 12:29 PM	#1
steveimpala Active Member Join Date: Oct 2017 Location: Wappingers Falls, NY Posts: 122	Engine code or date code? Question, my 1969 396 engine has the following stamp on the passenger side: 10 21 YS , is this a date code ? Thanks !

03-19-2024, 12:53 PM	#2
CAMAROBOY68SS Senior Member Join Date: Apr 2022 Location: Hillsboro, Oregon Posts: 501	Re: Engine code or date code? 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. __________________ The Twins: 1968 C10 SWB - Blue 327/5 Speed 1968 Camaro SS/RS - Blue 327/4speed C10 Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=833278 The "Others" 1933 Ford Pickup (Camaro in disguise) 2017 Camaro SS Life long Chevy guy

03-19-2024, 01:06 PM	#3
steveimpala Active Member Join Date: Oct 2017 Location: Wappingers Falls, NY Posts: 122	Re: Engine code or date code? Thanks !

03-19-2024, 01:09 PM	#4
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 3,075	Re: Engine code or date code? 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. __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com

03-20-2024, 04:43 AM	#5
steveimpala Active Member Join Date: Oct 2017 Location: Wappingers Falls, NY Posts: 122	Re: Engine code or date code? thanks !

03-20-2024, 08:19 PM	#8
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 3,075	Re: Engine code or date code? 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 __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com



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