66 coupe stamp pad

[John F.]

I'd appreciate it if you pad experts would look at the attached. My car has a build date of Jan 25, 1966. The block casting date is 7/21/65, and the pad, shown in attached photo indicates an assembly date of 9/21/65. I had the car judged at a chapter meet and while the pad caused some discussion it was accepted without deduction. Can anyone explain the wide separation in the dates indicated? most of the posts I've read on this subject seem to indicate that the time frames were much shorter. Does my pad appear as though it has been doctored or restamped?

John Farren

[Mike E.]

Re: 66 coupe stamp pad

John,
Read the Corvette Restorer, Vol. 26, No. 4. I documented a number of original cars with casting dates vs. stamping dates. That would answer that question for you clearly. In addition--the image that I see in your post causes me no heartburn at all.

[Chuck S.]

Re: 66 coupe stamp pad

They truly AIN'T making them like that anymore...I COULD be a monkey's uncle, but I'd buy it in a heartbeat. Doesn't look like it's even been re-painted.

To answer your question, in olden days, pre-Just-In-Time manufacturing supply was NOT an exact science...it depended on people planning the same way all the time (not possible), pulling the oldest one off the stack first (didn't always happen because humans were involved, and it wasn't deemed important if the engine was 1 month or two months old before installation), and the processes had to conform to the most economic way of building this stuff, e.g. in batches (we'll build big blocks this month, and small blocks next month...an exaggeration because the engines may not have even been built in the same plant, Tonawanda).

Many here have looked at enough dates that they know how the dates are going to fall on the MAJORITY of the cars...that doesn't mean they are ALL going to fall that way. That's why the six month period is used.

[John H.]

Re: 66 coupe stamp pad

A strict interpretation of the six-month rule would place this block four days outside of the "window" for judging credit.

[Chuck S.]

Re: 66 coupe stamp pad

Oh, uh...Well, in that case, I would have to get me one of those geeky telescopes to check for the presence of broach marks...hmmmm, something going on vertically on the pad there. (Only kidding John Farren. )

Seriously, John H., you know that General Motors never had any "six month rule"...they never discarded any engines past their expiration date. Serious Corvette students should trust the empirical rules of their teachers, but not blindly or strictly when the data doesn't quite fit IMO. Everything has to be examined in its entirety, and our wisest teachers know that.

Anyway, the chapter guys made a good call in my opinion. A better picture of the pad would be nice...but, from what I can see (without a telescope): if it's a stamper, it's a "Dusey". I would have to figure that anyone that's good enough to make/paint a stamp that looks THAT right would know the NCRS has an arbitrary rule, and wouldn't miss it by FOUR DAYS! (Doup!)

[John F.]

Re: 66 coupe stamp pad

Thanks Guys - I appreciate the info from all. I'm going to see if I can get a better picture over the weekend, and I'll repost. Thanks again.

John

[Gerard F.]

It has that crazy 9

(which could be an upside down 6 or small b) and the "I" instead of 1 on the date stamp, just like the one on my 67. Got to be original.

Jerry Fuccillo
#42179

[Mark P.]

Re: 66 coupe stamp pad

So what is the soonest an engine could be stamped and still correctly coincide with a particular vin? Could it be within a matter of as little as 2 or 3 days?

Thanks,
Mark

[Jack H.]

Re: 66 coupe stamp pad

Engines flowed from the Flint and Tonawanda assy plants while, asynchronously, the AO Smith and St. Louis lines produced bodies. Both sides of the equation were in a 'race' situation feeding the St. Louis final assy line. It's not impossible (and reasonably typical for AO Smith bodies) that an engine could be date stamped AFTER the body build date!

You go by VIN number of the finished vehicle and the 'birthday' of a given car is extrapolated by interpolation. UNLESS a given car went through final assy EXACTLY on an end of month production snapshot day, the interpolation method has some 'slop' in it.

While some birthday calculators are more 'intelligent' than others (comprehend recognized holidays and weekends), they just aren't smart enough to cover ALL the bases taking into consideration things like, authorized overtime, random line shut down events, line pacing (speed-up/slow-down), wild cat grivence walk outs, Etc. Therefore, it's almost impossible to 'peg' the EXACT day a given car was actually built.

So, the general rule for dating is parts must preceed the car's VIN build date by 0-6 to six months with the ZERO taken literally! If a given engine was assembled in, say, Tonawanda on the SAME day the birthday calculation said the car was final assembled in St. Louis (presuming that date is NOT an end of month production snapshot day), it'd pass judging scrutiny despite what appears to be an 'impossible' situation...

[Chuck S.]

Re: 66 coupe stamp pad

Im pretty sure this question has been discussed before on the Tech Board, and I don't remember the answer. Maybe it was casting date vs assembly date on the engine...in that case, I think the gurus said they knew it was possible.

In the case of the engine assembly date vs. car build date, the transportation time for the engine from Flint (late C2s and C3s) to St. Louis becomes problematical. It would have taken special shipping arrangements for it to have happened in my opinion; because of the expense, I doubt it was often done.

Someone that has good experience on the subject will have to help you with this question. If I were looking at such a car to buy (probably very expensive at market prices), I would be skeptical and back away. At my knowledge level, the risk/reward ratio is not good enough. I personally don't have to bet my money that my Corvette knowledge is flawless with those odds...too many other opportunities. JMHO for myself only.

[Kent K.]

Re: 66 coupe stamp pad

My one-previous-owner 1969 has a trim tag date of M06 (August 06) and an engine pad stamping of T0708LR (August 08). The engine which was assemble 2 days after the trim tag date has never been out of the car since it was installed during assembly. GO FIGURE !!!
BTW - 1969 calendar shows August 8 was a Friday.
Regards, Kent #6201

[Chuck S.]

Re: 66 coupe stamp pad

Good info for the poster, Kent.

I suppose it could happen this way: A fresh shipment of engines is loaded for St. Louis, and the last one put on the truck (train?) at Tonawanda is the last one built for that day. The transport departs immediately, and delivers them non-stop direct to St. Louis. The new shipment is immediately unloaded and shoved in front of older engines (not having ANY engines is NOT an option), and that same day, one of the new engines is grabbed for a job number.

An alignment of stars that probably didn't happen often. But, Kent, if YOU said it was bonified, I would pony up the money.

[Kent Patterson]

Re: 66 coupe stamp pad

i worked at the famed AO SMITH in granite city were they made the vette frames and to respond to the cast date vs the build date...it makes perfect since to me..i worked close with quality control and it was common practice to have parts/ assemblies rat holed in their rooms for weeks-months,,,,when the qc dept was finished with the part/assy's they were fed back into the production lines provided there was no part changes....with no regard or worries about the date stamping...i am sure gm had the same process....thanks kent

[Michael H.]

Re: 66 coupe stamp pad

Kent,

I agree, an engine assy date that's two days AFTER the body was built would be near impossible. (unless a service replacement engine was installed at the plant a few days after the car was built)

However, your 0708 date is actually JULY 08, not August 08, so your engine/body dates are ok.

[Kent K.]

Let's see, I still have all my fingers

Mike,

Thanks for the awakening. My BAD. "7" does represent JULY, not August. Sometimes my fingers just don't count the way they usto.

Hope to meet you in January. Sure missed you at Howey.

Regards, Kent #6201