XA Stamp on Stage 1 Block

Hi All,

Here are the XA numbers from my 73 Stage 1 Block and notice the slight stamp of the "S" that has me a little miffed. I am aware that the Skylark GS used XS in 73. Could it be that these Blocks were used at Flint universally, or they ran short and then Stamped at the final application. I can't explain it any other way. All the Numbers, VIN and so on are correct and I have extreme Documentation on the Car. This was a one owner Car by an Older Gentleman and I know the Car was never molested in any way. Any Opinions or knowledge about this ?

I am hesitant to respond because I'm not that knowledgeable on 70s stamps but here go's. So you have the XA and S. No Skylark in 73 but Century may have offered a high performance 455 in 73. I just don't know enough to be sure. But even at that I don't think the Century was being produced in Flint for there to be confusion within in that context. Probably made in Fremont CA but again someone correct me if wrong.

Aside from that, unfortunately for the number seeking person 40+ years later, incorrect engine stamps were not terribly uncommon. It was a manual human process to stamp the engine based on the car it was going into. Knowing how easily confused humans get with numbers, and the loosely run state of car manufacturing (compared to today) back in the 70s, its not hard to imagine errors happened and they seem to be more common on the special or low production models. I doubt stamps were part of quality control.

I am not familiar enough with 73 engine stamps to know how the spacing between characters compares to others of same year but right or wrong those do look like factory stamps to me.

you may already know the block will also have the VIN number on it to left of timing cover that matches the body VIN. Does that match? If so the XS/A stamp becomes less relevant especially with all the other documentation you have.

Hopefully someone with more knowledge on the subject will chime in

XS = Century GS Stage 1 (A-body cars built at Framingham MA, Flint MI, and Fremont CA in 1973 and only 728 Century GS Stage 1 cars built in 1973 and all 3 plants built Stage 1 cars)

XA = Stage 1 in Riviera or High Performance 455 in A-body and all other fullsize cars (LeSabre and Centurion) (1,234 Riviera's built with Stage 1 engine, 43,027 other cars built with Hi-Perf 455, fullsize cars built at South Gate CA, Flint MI, Fairfax KS and Wilmington DE in 1973)

As mentioned, stamping mistakes were common. Attached are pictures of other engine production codes, all with three letters instead of two. My guess is that they re-stamped them as needed.

XS = Century GS Stage 1 (A-body cars built at Framingham MA, Flint MI, and Fremont CA in 1973 and only 728 Century GS Stage 1 cars built in 1973 and all 3 plants built Stage 1 cars)

XA = Stage 1 in Riviera or High Performance 455 in A-body and all other fullsize cars (LeSabre and Centurion) (1,234 Riviera's built with Stage 1 engine, 43,027 other cars built with Hi-Perf 455, fullsize cars built at South Gate CA, Flint MI, Fairfax KS and Wilmington DE in 1973)

As mentioned, stamping mistakes were common. Attached are pictures of other engine production codes, all with three letters instead of two. My guess is that they re-stamped them as needed.

Stamp in the first pic doesnt look "right". Maybe because it is highlighted? Is the production number "38I" ? Or is it 381 ?

Tom

Highlighted with chalk to make it easier to see. I=1, b=6, upside down b = 9, so the number is 381

Highlighted with chalk to make it easier to see. I=1, b=6, upside down b = 9, so the number is 381

But they used a 1 in the Engine Serial Number (VIN) ??????? I've seen 1's in tother production code numbers but never an I substituted for a 1.

Ed

Buick used an I for 1, etc. for a very long time. There was an article in the July 2013 Buick Bugle that talked about this. I don't know why they used both, but they did. Do you need pictures? I have hundreds.

If you look at the picture in the original post you will notice it say I72 after the S.

Highlighted with chalk to make it easier to see. I=1, b=6, upside down b = 9, so the number is 381

Sean, The stamps are often partial or corroded so fine details are difficult to discern but I would expect a "1" to appear in the mid sixties Nailhead stampings...but that was obviously up to the individual who loaded the character. Also, one of the letters as well as the "I" are off plane. This seems logical as one of the alpha characters is obviously "extra" and possibly added after the initial stamp but the production # should have been stamped just once. Perhaps a mistake was also made on the initial # stamp and the "1" omitted and the "I" utilized to make the correction?

Do you have pics of any other mid sixties Skylark stamps?

I have witnessed 3 character alpha stamps in the past including a very interesting "MXZ" stamp which, in my opinion, was original.

Tom

They didn't always get things in a straight line and, as the picture in the original post shows, what you expect to see isn't always what you find, but that doesn't mean it is not original though. Buick has a long history of using I's and b's, back to at least the mid '30s for engine stamps and back to the early '30s for frame serial number stamps.

More pictures.

Last set, but only back to 1955. I know you only asked for mid 60's Skylarks, but I included some from all models from the '50's and '70's because focusing on one model for only a few years does not give you an accurate idea of what they really did. You need to look at all models over a large range of years.

No one has point out something interesting about some of the pictures in my first post. Two of the pictures in my first post show:

RDR 216

RDR 48

RD = 430 V8

RR = 400 V8

mstanleyfl tried to post this and it got deleted, probably due to an incorrect link. Here it is with the correct link:

Not Buick but a touching story about ID plates. See page 3:

http://www.tucsonbritish.com/Newsletter/2014/November_2014.pdf

A few excerpts from the July 2013 Bugle.

Thanks for all the input, interesting. Of course all the numbers match up with the proper VIN on the Block. I'll always believe the engine was destined for a Century and was restamped when it went in my Riviera. My Car was Ordered as a Stage 1 only with no GS option so thats strange to start with. Probably the only one.

Last set, but only back to 1955. I know you only asked for mid 60's Skylarks, but I included some from all models from the '50's and '70's because focusing on one model for only a few years does not give you an accurate idea of what they really did. You need to look at all models over a large range of years.

Sean,

I asked for Skylark stampings because I wanted to see the same character stampings for an apples to apples comparison. There is another observation I have come to learn about mid 60`s engine stampings which I hesitate to elaborate upon because I`m concerned, given the trend I have seen develop in the muscle car craze, about providing cloning info.

BTW, I both agree and disagree with your reasoning regarding stampings.

To draw conclusions based on very general trends it`s great to see a wide variety of samplings but for very specific peculiarities I`d rather eliminate as many variables as possible...same plant, same management directives, same stamps, same employees, same circumstances, same purpose or goals, etc...

Very nice sampling of pics. I wish I was so diligent, thanks,

Tom