I just purchased a 1968 350 two barrel convertible, with tons of documented history, 1 Family car. I'll go into detail on another post.
I really wanted to confirm original motor, I located what I thought was the VIN stamp on the motor it reads as follows....
28U163637

My VIN reads 223678U163638.....

If the stamp on the motor is not the VIN stamp then it is eerily similar. If it is supposed to be the VIN stamp it is basically 1 digit off???? I have a decent picture of the stamp... I am pretty clear on the 7 not being an 8, and pretty darn sure about the 2 not being a 7.

Whats the deal? Could someone have forgotten to switch the stamp machine and marked more than one motor with this number since it is only one off????

I have only researched a bit on this site as to the location... this stamp was located (As facing the car) to the left of the balancer on the front of the motor, behind the lower radiator hose.

Thanks for any help

That happens from time to time. There is a 69 T/A out there that has a Camaro Vin stamped on it's original block.

it's not wrong

pontiac division uses a "2" on the engine stamp to denote their division

2 = pontiac
8 = 1968
U = Lordstown
etc.

the only thing that would make a "Camaro" VIN appear on a Pontiac block is if read 19U1XXXXX instead of 29U1XXXXX

OK, that explains the first number, but what about being 1 off from my VIN,
3637 vs 3638

Thanks

the assembly tech didnt reset the stamp after stamping the car ahead of yours on the line

That makes sense to me, however, will I run into issues down the road on resale etc. or issues with being "numbers matching"?

Thanks

Not likely as you can show by date codes that the parts are appropriate. Unless it is an extremely rare car, I.e. Ram Air optioned, it won't make a huge difference.

It's still obviously the original motor. What are the odds of somebody swapping the motor with a motor with one number off? You're not the first person I've heard with this issue. They probably stamped the motor at some point before installation and something happened on the line where there was an issue with a body or motor and things got out of sync. There may be a whole batch of birds along with yours with the motor numbers one off.

Thanks for the information, This is kinds what I was thinking but wanted to make sure I was not off base.

OHCMarc, a member here has the same issue. Maybe pm him. He did some research into his.

His issue was then body stamp VIN
https://firstgenfirebird.org/forums/ubbth...4417#Post274417

Hi, I presume you got your PHS docs correct? Match the 2 letter engine code to code circled on the "Engine I.D." page. Match the engine serial no. to "Engine Unit no." on the "1968 Car Billing History" or build card.

Match partial VIN to last 8 or 9 digits of full VIN.

If you got all or most of that matched then your good to go. 1 or 2 digits off ... probably a Monday build day after SuperBowl.

Your VIN decodes to: 1968 Pontiac Firebird V8 Convertible
This car was assigned the serial number 63,638 at the Lordstown, Ohio plant.

Use the VIN analyzer to decode it for you. https://firstgenfirebird.org/vin-analyzer/

I have a 68 350 convertible with the exact same problem. I contacted PHS and they said that is fairly common and not to worry about it. They must have gotten one engine behind when they were matching with the bodies. It may have gone on for some time as my serial number is about 2000 ahead of yours.

I am looking at another motor and VIN stamp is 29E167399, I am assuming then that this is a 1969, which seems to match the YD engine code... is there a way to tell then if this was even a firebird motor, or what type of car it came out of.... thanks

"E" = Linden, NJ. No Firebirds built in Linden. Catalina and Bonneville - maybe Grand Prix