I did some research a few weeks ago on bogus VIN stampings on engines and transmissions. This week I'm looking at another 4 spd. where the stampings form waves rather than 1 fairly straight/ramped line. I've read where these were stamped in gang fashion so the numbers should generally track in one direction (up, down, or sideways, not 2 or 3 directional changes). In particular:

Engine VIN stamping forms a cosine wave with first 3 digits angling back downwards, the next 2 angled upwards, and the last 3 generally even or slightly curve upwards. Basically 2+ different levels represented. The fonts seem to be very similar to what's on the trans. The numbers are fairly evenly struck and easily visible.

Transmission stamping is much fainter than the engine stamping with the lower and left sides of all digits partially missing. The last 2 digits are hard to make out. The stamping here is more like a sine wave starting out low and sloping up for the first 3 digits, then sloping down for the next 2, then fairly level for the last 3. Again, probably 2+ different levels.

Would these two stampings have been done at the same time by the same person, and if so shouldn't they be similar in slope and depth rather than a mirror (inverse) image? Or can these type of irregularly curved stampings occur on the production line?

Car does have fender tag, build sheet, decent owner history but to me those are separate issues from the drivetrain. No sense in looking further at such a car if the stampings are potentially in question.

Thanks

RR69s

This help...

1_Wild_RT,

I think you just blew a big hole in this for me. I've only looked at VIN stampings on 4 spd GTX's twice in my life and one of those was a hemi. And for some reason I'm thinking on the 833 that it would be down on the passenger side machined pad. But now I think I remember seeing both numbers up top on the bellhousing as your photo shows. The trans stamping on this 4 spd is on the side of trans like 69's. So this this already feels really bad to me. The engine stamping is on the upper bell housing where it should be (as photographed).

I also broke down the 4 digit factory date code (10,000 day calendar) on the trans and it was January 15th, 1968...so a mid-year car that should have followed all the typical rules. I had a 4 speed GTX conv years ago and I think the PP883XXXXXXXX trans serial number was stamped on the side of the trans while I'm unsure on the VIN.

RR69s

Actually on a 68 4spd the vin is on the side pad..

1968 Automatics - stamped on the bell.

1968 Manuals - stamped on the pad.

One of the stamps in that photo does not look like the other one to me either.

Funny thing is it's a picture that I grabbed off Moparts when Doug posted it...

It would be cool to see a straight on shot just to eliminate any distortion from the slight angle.

OK, so much for my memory from 14 yrs ago. These VIN stampings are in the right place. So back to the original question about the 3 wave pattern to each of these stampings. And the waves are inverse images which means to match that you'd have to stamp one of them upside down.

Is this possible or not? One would think that a restamper would be able to get a reasonable alignment. The factory on the other hand probably wouldn't even care.

RR69s

I agree, I've looked at it before & I thing it's legit just the angle/lighting/paint remains...

The numbers can be up or down because the stamps were on a dial. I am not sure what you mean by inverse / upside down though?

Photos?

The first 3 numbers on the trans slant sharply upwards, yet on the engine they slant sharply downwards. Shouldn't they be slanting in the same direction if produced from the same stamping equipment? So in effect they actually appear inverse or mirror image to one another. The photo above on the automatic - both of these are essentially level all the way across and a mirror image. On my car the 3rd digit on both the engine and trans. is basically one half digit in width offset from the 1st one. Seems like a lot of slop even for antiquated equipment.

The 97622 on the passenger side of the trans doesn't match up to the 6 digit part number or the last 3 digits of the Code # which appear on the build sheet. Is that a casting number?

Ok, working to get 2 photos posted.

RR69s

The photos, engine first;

Transmission;

i am not sure how much of these stampings were done by machine,or how much was done by "hand". this is a pic from a 1973 340 block,untouched or messed with (machine marks from fly-cutter on pad very visible) and if it was "machine" or "dial" stamped,then that equipment had major issues.

Thanks for posting those photos Barry.

That 73 340 block looks pretty strange with a tripling of the first digit only. One wouldn't think a machine did that. At least they are all in somewhat of a line with slight tweaks up or sideways.

RR69s

I'm understanding that on the trans the first 3 numbers are aligned like stairs going up, and on the engine they are like stairs going downward.
It is not likely that the stamped numbers will have the same orientation. I've seen instances where engine and auto trans are stamped (adjacent)and the digits do not have the same alignment.
In one case the number 8, for the year, is actually upside down on both lines so I know it's highly likely that it was the same tool.
I think the individual dies were loose in whatever fixture held them and minor misalignments are common.
Font style is a good indicator as is original machining on pads.
Also it's good to check assembly dates on components and to compare known so to vin sequence of the plant the car you're looking at was built.

There were many variables between plants as well as model years, there's no "one way" that's correct accross the board. I'd post (allot) more info but it would be helping the crooks out there get better, simply not going to go there.

To the OP, if you really want to know what you've got I suggest hiring an expert to check it out, or at least get (high quality) pics of the stampings, preferably with all paint and grease removed first, and post them here.

few things i dont like, the bell flange stamps seam to light, and to wavey. all the late 68 hemi blocks ive had there are stamped way more inline, and block almost cracking deep. also i dont see broach marks under trans stamp,those do get wavey,many have been angle ground right above mopar type set case#s, and restamped