[19652plus2]

I'm looking at a '64 GTO that has an idento plate that shows 76W for the engine block, yet the car's actual block has a 76XW. The EUN is the same on the block and idento plate. Should I be alarmed at this "discrepancy" ? I'm looking for an original engine car.

Thanks

[pfilean]

I thought 76X was 3x2 3 spd and 76W was 3x2 4 spd. There may not be any difference if the bell housing is the same so maybe some got double stamped to use either way.

[Keith Seymore]

Originally Posted by 19652plus2

I'm looking at a '64 GTO that has an idento plate that shows 76W for the engine block, yet the car's actual block has a 76XW. The EUN is the same on the block and idento plate. Should I be alarmed at this "discrepancy" ? I'm looking for an original engine car.

Thanks

If the EUN on the block matches the protecto plate then it is the original engine (assuming the block has not been restamped).

K

[Old Man Taylor]

My '64 tri-power 4-spd car was 76XW, but the W was faint and not in line with the 76X.

[johnta1]

The way I got it is the 76X is basically the manual tranny engine for the GTO.
(3 speed)
They added the 'W' if it was to have the wide ratio tranny.
The '9' was added for the close ratio tranny.

The POP just shows the engine 76X, probably has a designation for the tranny on it?
(not sure I've seen a POP for the 64 GTO)

[19652plus2]

Originally Posted by Old Man Taylor

My '64 tri-power 4-spd car was 76XW, but the W was faint and not in line with the 76X.

Same stamping with this car.

[Ram4king]

Same way on my 64 convert. Untouched survivor. Looks like its right on the money.
Like John said, W is for wide ratio trans. When there's just 76x that's for a 3 spd.

[Tom Vaught]

X3, EXACTLY the way mine is stamped too. 76X on the block and then the "W" was stamped obviously at a different point in time.
All characters are close but easy to tell two different stampings happened.

So you have a GOOD ONE THERE, everything looks good on the parts matching.

Tom V.

[johns]

X4.

[John V.]

Assuming it is an original '64 Ident-O-Plate (forerunner to what was later called the Protect-O-Plate), the fact that the Plate was coded 76W was either the standard practice at that Plant or else a simple coding error by the guy who produced it.

As the others have described, a '64 GTO Tripower engine intended for manual trans application left the Pontiac Engine Assembly Plant coded 76X.

If the car was built with the standard floor shifted man trans, no Secondary Trans Code was to be added at Final Assembly.

If it was equipped with any factory ratio except 3.90 and also the 4 spd, the Final Assembly Plant was to add a "W" so that the engine code would read 76XW.

As others point out, the Final Plants haphazardly stamped the "W" so that they will be found before the 76X, after the 76X, on top of the 76X, or possibly even forgot to stamp it.

If you got the 3.90 axle with the 4 speed, you got the same wide ratio Muncie but with a 6 tooth instead of 8 tooth speedo drive gear for speedo accuracy and the Final Plant was to add the Secondary Stamp Code "9" so that the engine code would read 76X9 (with the same haphazard locations possible for the "9").

Late in the year, you could special order the close ratio Muncie but only with 3.90 axle and Tripower. In that case, the Final Plant was supposed to stamp an "8" so that the engine code would read 76X8.

NOTE, despite what many references have claimed, the "9" does NOT indicate a close ratio, just a wide ratio with the correct speedo drive gear internal to the trans for use with the 3.90 axle.

If your car happens to have been built at Kansas City, an imprint of the original Ident-O-Plate was made on the Shipping Order record that you can obtain from PHS.

If your Ident-O-Plate is original it should exactly match the imprint on the PHS document since it would have been the one used to make the imprint on the document.

If the 76XW stamping on the block looks "perfect", you might want to get a pic of it and compare that to factory original stampings of '64 blocks. Originals are more likely to look "imperfect" as far as the placement of the "W".

It is kinda difficult to restamp with the exact '64 fonts for each character. Wrong fonts will be very obvious.

You can also obtain the cast date of the block and the Engine Unit No. and I can compare that to my log of '64 engines for you.

If the cast date is obviously wrong for the EUN, I can detect that. Won't necessarily be able to detect all restamps this way but if you are concerned, it is worth checking all possibilities.

Since the Ident-O-Plate provides the original EUN, a restamper would have no trouble stamping a matching code and EUN for the GTO. But if he started with a cast date block that wasn't possible, that can be identified.

Of course, I've been told that at the high end of the hobby, folks have redone cast dates with a little brazing rod magic.

So at the end of the day, it is really difficult to know for sure if a block is original to the car no matter what the litmus test.

I don't think having the Ident-O-Plate show 76W is cause for alarm.

[19652plus2]

Here's the stamping. I don't have the block casting date yet, but the car was built April 9th at the Pontiac plant.

[Ron Landis]

what about an April Fremont 3.90 gear car?

[Old Man Taylor]

Originally Posted by 19652plus2

Here's the stamping. I don't have the block casting date yet, but the car was built April 9th at the Pontiac plant.

That looks good to me.

[19652plus2]

Here's the block casting date.

[Tom Vaught]

John V can speak far more accurately on this subject but If the block was cast up on April 7 1964 and it still needed machine work on the block (one day minimum), I find it hard to believe that even Pontiac Engine Plant could then assemble the engine and install it in a car the next day at the Pontiac Assembly Plant. But on a 3 shift operation deal it might be possible.
That is the closest Engine Date vs Vehicle build I have ever seen.
But I look at KC built Vehicles normally and the GTO engines had to be shipped from Pontiac to KC which would take some time.

Keith Seymore would be the expert on that Pontiac Plant Build capability.

Tom V.

[johnta1]

NOTE, despite what many references have claimed, the "9" does NOT indicate a close ratio, just a wide ratio with the correct speedo drive gear internal to the trans for use with the 3.90 axle.

Yes, I was thinking '8' but CRS strikes again.
(or find my pic I posted somewhere on PY)



Should have looked it up instead.

Thanks for the info, John!

[John V.]

EUN 405888 is a decent fit for a Block cast D74. I have a record of a Block cast D114 with an EUN of 414XXX. I also have logged a 414XXX with a D14 cast date but that one was either misread (logged decades ago, maybe was actually also D114) or else it is a slight anomaly and was a bit late to get pulled from the stack and assembled into an engine. Just to be clear, this was NOT unusual, the Blocks did not go to machining and engine assembly in a first in, first out inventory control manner. Instead, more likely they worked thru them in what was probably more of a last in, first out manner. So when a new batch of Block castings came over from the foundry, they "jumped the line" ahead of any older blocks that were already in the "stack" awaiting processing. Just my theory based on what I have logged.

The EUN and 76X stamping fonts look correct to my eye and the Secondary Trans Code stamping "W" also looks like the proper font.

The Pontiac Engine Assembly Plant was cranking out about 60,000 engine assemblies per month around March/April or about 2500 per production day, about 1/2 installed at the home Pontiac Assembly Plant, the rest distributed to the various satellite Assembly Plants around the country.

Lots of examples in '64 where the Block cast date seems impossibly close to the Final Assembly date at least according to the Time Built Code on the Data Plate. This has proven true for builds at the Pontiac Plant but also true at the satellite Plants despite the transport time as Tom points out. At the Final Plants, there was also no apparent first in, first out install of the Engine Assemblies. A later EUN may have found a home in a car before an earlier EUN. You can make some generalizations that normally hold true but there are exceptions that also did occur. Among the things that you know could NOT have happened was for an April assembled engine to have been original to a car that was built in January for example. But while it would have been very unusual for a March assembled engine (not just cast but actually assembled in March) to sit uninstalled until a late May build, I once documented that very thing for a '64 Fremont Lemans with its original 4 bbl 326 engine.

My log has recorded info only from the block and data plate. I did not have access to the PHS doc.

Since it is impossible to know what the Production Date on the Manifest actually represents, we can't really know if this car was "completed" on April 9 or perhaps production began on the Body Assembly in the Fisher Body Plant on April 9.

What is the Time Built code on the Data Plate?

What is the date code on the Ident-O-Plate, I suspect D94 but worth confirming?

Regardless, without any suspicious indications for the engine block stampings and the fact the EUN is confirmed by what would seem to be the original Ident-O-Plate, I would have to conclude the original block is in the car.

Ron, not sure what you are asking, Fremont added Secondary Trans Codes same as all other Plants.

In all likelihood, an April built GTO with 3.90 axle and 4 spd from Fremont would have gotten the regular production p/n 9774826 Muncie trans, wide ratio M20 with the 6 tooth speedo drive gear (9774825 had the 8 tooth speedo drive gear for use with all other factory offered gear ratios).

Fremont would have stamped the "9" code on the 76X or 78X block depending on whether it was a Tripower or 4 bbl build.

I don't think the close ratio Muncie had yet to have become available until at least April and unlikely to have been included in any builds until May, but if so equipped, the PHS doc for a Fremont build will show the M21 code and the Sales Code 778 so they are easy to identify from the PHS.

Tripower was required if you wanted the close ratio and Fremont would have stamped the "8" so that the engine code would have read 76X8.

The 3.90 could be ordered all year, long before the p/n 9777000 close ratio was made available.

Only know of one close ratio equipped '64 GTO ever built, it was built in May at Fremont.

The rest of the '64 GTOs with 3.90 axle and 4 spd got the "9" stamping, 3.90 was available for BOTH 4 bbl and Tripower. They always got the M20 2.56 1st gear Muncie.

The close ratio had to be special ordered, it was never included just because you ordered 3.90 gears.

For some reason, a lot of guys who ordered '64 GTOs new thought they were supposed to get the close ratio when they ordered the 3.90 gears. That was probably the main reason why researchers believed for years that the code "9" indicated a close ratio. Then when they discovered all the GTOs with the code "9" actually got a wide ratio trans, they speculated that PMD substituted the wide ratio because of a shortage of close ratios.

All of that was nonsense. PMD installed the p/n 9774826 trans by design for the 3.90 GTO builds and it was never intended to be a close ratio. The late year release of the p/n 9777000 trans made the close ratio available but they are extremely rare, doesn't seem that the availability was very broadly announced.

The close ratio was mentioned in the April 17, 1964 reprinting of the GTO Sales Brochure (no mention in the original GTO Sales Brochure). But unless the salesman knew how to get it special ordered, it would still be omitted from the build even after it became available.

John, no sweat, I have to "relearn" stuff about the '64 all the time. Hard to forget old and long held knowledge that is later disproven!