engine assembly code
 

wanted to confirm that this motor is original 402 as the previous owner indicates. I have the assembly date code off the block from the deck just in front of the passenger side head, have a pick of the casting code also but it isn't legible until I can get it cleaned off. I'll post the pics, the assy code is T1223TKB. I'll post both pics as well maybe you have a better eye than I do.
http://pic20.picturetrail.com/VOL122.../351816698.jpg
http://pic20.picturetrail.com/VOL122.../351816732.jpg
http://pic20.picturetrail.com/VOL122.../351816757.jpg

thanks,

Dan

:gmc2:

Re: engine assembly code
 

TKB suffix code= 1972 402 big block

Re: engine assembly code
 

OK, I just found that, it also lists 71 402 with 310 HP. so what does the T1223 stand for?

Re: engine assembly code
 

Doesn't the T stand for Tall Deck?

Re: engine assembly code
 

couple more pics
http://pic20.picturetrail.com/VOL122.../351819626.jpg
http://pic20.picturetrail.com/VOL122.../351819605.jpg

Re: engine assembly code
 

According to MorTec, if it's 3969854, which is what I'm seeing here, it could either be 70-72 402 or 69 396. What do you guys think? Probably original motor?

Dan

Re: engine assembly code
 

On the page where it explains the TKB code on nastyZ28 site it shows L-47 10,20,30 under comments. Anyone know what that means?

Dan

Re: engine assembly code
 

c-10, c-20, c-30. 1/2 ton, 3/4 ton, 1 ton trucks L-47 was the production code. it is probably the original engine. My 72 big block is a TKX suffix code, under comments it lists 20, and my truck is a C-20 3/4 ton

Re: engine assembly code
 

The stamped numbers should match the numerical part of your trucks serial number if it is the original engine.
As those of who watched part or all of the Barrett-Jackson auction this weekend can attest.
If they don't match it most likely shows that the block was swapped out at one time or other.

If the engine and trans both are original to the truck both will have the same number as the cab and chassis.

Re: engine assembly code
 

Cool, is the serial number part of the vin? Does this rule apply to GMC trucks as well?

Re: engine assembly code
 

Ok here's the SPID and what looks to me to be serial number plated on the door and door jamb. This indicates that it's not original then?

http://pic20.picturetrail.com/VOL122.../351837213.jpg
http://pic20.picturetrail.com/VOL122.../351837333.jpg
http://pic20.picturetrail.com/VOL122.../351837269.jpg

If true I will be sad.

Dan

:gmc2:

Re: engine assembly code
 

its possible the engine was replaced under warranty for some reason, that would be close enough to factory for me:)

Re: engine assembly code
 

Does anyone have a link to a site that would allow me to decipher the vin code or assembly code for the motor for GMCs? I'm having trouble finding anything.

Re: engine assembly code
 

OK, I need to look for another number in the same stamped location that refers to the vin code. This number indicates that it was assembled at the Tonowanda factory (T) on Dec (12) 23rd (23) and we already established what the TKB stands for. I found a site that lists this and shows an example. I'll try to upload the photo and post it.
http://pic20.picturetrail.com/VOL122.../351868489.jpg

I'll try to see if I can uncover this number from the block now.

Re: engine assembly code
 

Clearly, there is no number located on this deck. Here's a picture.
http://pic20.picturetrail.com/VOL122.../351869653.jpg

I think there are other locations on the engine for this information, so I'm going to see what I can figure out. Any info or advice would be helpful.

Dan

:gmc2:

Re: engine assembly code
 

OK, according to the sticker on the door jam, the truck was built in Jan 1971. The stamped number on the block indicates the engine was assembled on December 23rd and the suffix code indicates it is a 1971 402 for a Truck. I cannot find the stamping that would have the production number, it is missing from the position on the front of the passenger head that the site I was looking at refers to. There is another place to look according to the site near the oil filter, so I'll try to find it tomorrow. My thinking is that it would be very difficult to have an engine assembled in December on a truck assembled in January and it not be the original engine, but I won't stop until I have definitive proof.

Any other ideas on how to find this?

Thanks,

Dan

:gmc2:

Re: engine assembly code
 

bump!!

Re: engine assembly code
 

Has the engine been decked? If so, I have heard that will remove the other numbers.

Re: engine assembly code
 

Since the assembly date code T1223TKB was found on the deck, I don't think it was decked. According to a web site I found, the vin code is sometimes found in other locations, so I'll be trying to uncover it in the areas specified.

Dan

:gmc2:

Re: engine assembly code
 

bump

Re: engine assembly code
 

one more bump

Re: engine assembly code
 

I think the partial VIN on the engine rule only applies to cars, not trucks. I bet it's original.
Someone here knows for sure...

Re: engine assembly code
 

They didn't put the VINs on truck engines. From the dates and codes you listed, it looks to line up. There is a cast date on the block under the passenger exhaust manifold. Check to see what this date says. I'll bet it's nov or dec of 71. Which would line up. But, from what you have already described, I think you have a match.

Re: engine assembly code
 

I know they didn't put the entire vin code on the engines, but they did stamp the assembly date code, the suffix code-telling you the engine size, hp, vehicle type, and sometimes tranny and the production number of that particular style for the year, which is the last part of the vin and from what I've been told and have read from multiple sources, that is how you determine engine/body/frame matches. For this truck it would be 14211, which indicates that it is the 14, 211th truck built in that year. If you look up in one of the pictures I posted, it shows that code in smaller stamp letters on the deck just right of the assembly code. I'll repost the picture here with the caption below it so maybe some of what I just stated makes more sense.
http://pic20.picturetrail.com/VOL122.../351868489.jpg
Stamped assembly code and portion of the “VIN” number on the front pad of the deck. This was found on a 402 block cast on 4/27/71. “TO5O4CLB” translates into a 402/300hp engine made at the Tonawanda factory (T). On May 4th (month 05, day 04) it was placed into a 1971 Chevelle and was mated to a Turbo–400 automatic transmission (CLB). The “11C166486” relates to the VIN and body style of the Chevelle. From the stamped engine assembly code and the block casting date we can tell that the engine block itself was cast and then 7 days later the fully assembled motor was placed into this vehicle.

Re: engine assembly code
 

There is no, repeat no vin # stamped on a truck motor period.