[veet66]

I have a 65 GTO convertable. It is a real GTO tri power per PHS papers. When I purchased the car I knew it was not the original engine but was told it was a tri power engine. Here is the question. On the engine block it is stamped WS Y G then below it is the numbers. I looked up Y G and there was no engine with Y G in 65. I thought it may have been a restamp or a dealer replacement. Maybe it could be used on other replacements. The odd thing is WS is together and Y G is spaced out. I will try to attach a picture. Any ideas. Where did the WS sit above the numbers. to the top left, center, or right of the top numbers.

[gtojon]

Did you check the casting date that is cast into the block behind the distributor hole? This will get you your block year, if '65 or not. Then you can also check the block casting number to see if you have a 389,400,421, etc.

[Fill Zerbe]

Here a picture of a tri power block.

[johnta1]

WS is the engine code of the engine.

Should look like the pic posted.

Have a pic of yours?

Here's a web page to look at:
Engine Codes

[Keith Seymore]

Sidebar:

Is the car a 4 speed?

If so, these gentlemen would be interested in your build information to complete a registry that they are working:

http://forums.maxperformanceinc.com/...d.php?t=650449

Please share whatever information you are comfortable in letting them know.

K

[John V.]

Actually, there was a YG code Engine for '65, not sure where you looked up the '65 codes?

YG was a Tri-power big car motor for an auto trans application. It was NOT the HO version, was assembled with regular big car log type exhaust manifolds.

You would not find an Engine Manifest Code or Engine Unit No. on a Service Replacement fitted block. The Engine Manifest Code was only useful for identification for final assembly, it would have no relevance for Service.

PMD generally did not sell complete engine assemblies for service replacement, so there would have to be another explanation for the two different Engine Manifest Code stampings on your block.

I suppose somebody could have taken a WS code GTO engine and restamped it YG to stick in a big car resto. However, I think restamps are more common in the GTO hobby.

Why somebody would bother to stamp a WS on a block without first grinding off the original code stamp is beyond me.

Often you can tell a restamp by comparing the font of the stamp. Compare your WS with the one in the pic (assuming it is legit). If your characters appear shorter, wider, or otherwise don't match exactly, likely it was restamped.

I'm not aware that the location of the letter code is in a consistent location relative to the EUN since I think they were separately struck.

The same 389 block p/n was used in '66 but there does not appear to have been a '66 YG so for the moment I'll assume the block was originally part of a '65 Engine Assembly.

Depending on how meticulously converted to man tran specs, if it was originally a YG, there may still be vestiges of the auto trans paraphernalia associated with the carbs for example that will identify it an originally intended for an auto trans application.

[veet66]

The number on the back top of the engine by the distributor is 9778789 which I believe is correct for 1965. Also at the same location is a number L114. I believe that number represents a Dec. 11 1964 date. It is a 4 speed. I still am having a problem trying to attach the picture of the engine number.

[John V.]

You are correct about p/n 9778789 and the L114 cast date code. As mentioned, 9778789 was also used for '66, but with the Dec. '64 cast date, you can be 99% certain the block was originally part of a '65 Engine Assembly.

Posting a pic of the code and Engine Unit No. may be useful to others here that will be able to discern (better than me) if the WS or YG was more likely the original manifest code.

Not sure what you were told when you bought the car, but sounds like the seller gave an honest description, the engine was a non-original but a real '65 Tripower YG that was swapped out of a big car at some point and wound up in your GTO. All the better if your car is a mid Dec thru early Jan build, since the cast date would be a good "match" to your car.

To post a pic, when you are composing your reply, scroll down and click on "Manage Attachments", then browse to the location where your jpeg is located on your computer. Doubleclick the jpeg, that will return you to the Manage Attachments page, then click "upload". Once it finishes uploading, click submit reply and the pic should be attached to your reply.

If the jpeg is too large a file, you would have to resize it smaller, or take a pic with a lower resolution setting on your digital camera.

Hope that helps.

[veet66]

Thanks John V. Here is the pic. is it a WS or YG engine block? Or is this a one of a kind where it is worth $100,000.

[Greg Reid]

That's pretty interesting. Never seen an engine with two codes. I'm no expert and the pic is very small...but they look kinda authentic. I mean, who'd fake one like that?

[John V.]

Just to be clear, there was no such thing as a specific WS engine block. All '65 389 Engine Assemblies used the 9778789 block.

The code was assigned to identify the complete Engine Assembly as produced at the Engine Assembly Plant at the Pontiac, Mich complex. Each Engine Manifest Code had a recipe for what was assembled in and on the block for each application.

Engine Assemblies did not include carbs but did include exhaust manifolds, intake manifold, cam, crankshaft, pistons, flywheel, heads, and a host of other items. Many items were common to multiple code engines.

A YG differed from a WS by virtue of the exhaust manifolds and flywheel (auto trans vs. man trans).

On occasion, the factory might have mismarked an engine assembly, but typically they would have "X'd" out the wrong code and struck the correct code, otherwise the Final Plant would not have been able to identify the intended application, at least not easily.

I am not familiar with the '65 engine stampings, so I am not real sure the pic Fill Zerbe posted is actually a correct factory stamped '65 WS. It seems odd to me that the WS on that one is struck below the Engine Unit No. Going by memory, I thought the Engine Manifest Code was always above the EUN in '65. It might have been moved below the EUN in later years. I'm just not sure. For '64, I think the Engine Code was always above. Maybe somebody else knows for sure about '65.

And your pic is very small.

But comparing the W's, yours appears to be a different font, notice that the other W, the center "tip" is lower than the outside tips, your tips appear to be all the same ht.

That would be a tip-off that the WS on yours was added later and most likely the YG is original.

As far as the letter spacing, the YG spacing looks more factory correct to me.

Are the heads and intake date code matched to the block? Are the carbs auto trans units? Are the exhaust manifolds NOT date matched to the block (since the YG LH manifold would not fit a GTO, at the very least, the LH manifold would have been changed if the Engine was originally a YG)?

These and other clues would tend to prove the block was orginally part of a YG Engine Assembly and the WS added to give a bit of an air of "correctness" when it was swapped into the GTO.

Unless some guy steps up and says he did the stamping, I don't know how you will ever know for sure. Truth is, it is VERY difficult to prove a restamp if it is done very well. In your case, there does not seem to have been an attempt to disguise the fact that a stamp was added and still we're not sure what happened!

[60sstuff]

The Red on Red 65 Tri-Power 4 spd. Survivor from an old ebay auction shows the WS above the number.

[johnta1]

That's a Fremont WS/car.

veet66, is your car a Fremont car?

[Greg Reid]

May not be significant but I noticed that the 'WS' on 68sstuff's example and on Fill Zerbe's example is far over towards the right edge of the EUN...and that's where the 'YG' is on the subject engine.

[Fill Zerbe]

Picture I posted is from a car build at the Pontiac plant. The date code on the block is
E75 and the tripower manifold is also has a date code E75 if that helps.

[johnta1]

That would make sense.
Most plants stamped the engine ID below the EUN, except Fremont did things differently.
Theirs were sometimes above the EUN.
(later years with partial VIN stamps, they were up there too sometimes)

[John V.]

John, the EUN and the Engine Manifest Code were both stamped on the block at Pontiac's ONLY Engine Assembly Plant at the Pontiac, Mich complex when the Engine Assembly was produced prior to distribution to the Final Plants. The Final Plants had no role in those stampings, they received complete Engine Assemblies already identified by Engine Manifest Code, ready for engine dress out and installation on the final line.

The Final Plants stamped secondary trans codes as specified adjacent to the primary engine code such as was done in '64 but I'm not aware of any secondary trans codes in use after '64. They also stamped the full VIN on the block thru '63 but that practice was ended, no VIN stamping from '64-'67.

Starting in '68, the Final Plants stamped the partial VIN.

If there was any variability in where the Engine Manifest Code was stamped relative to the EUN, it happened at Pontiac's only Engine Assembly Plant, nowhere else.

I do not ever recall seeing any variability for '64, the Engine Codes (27P, 78X, etc.) always stamped above the EUN.

I have not researched the '65 blocks so less certain about them. Examples I've seen for '69 seem to place the Engine Manifest Code below the EUN.

I have heard that the Fremont Plant was less consistent than some with where they placed the partial VIN stamp in the late '60s, early '70s but that is unrelated to this discussion.

[bigpop]

My 65 WS is above the EUN on the center/ right top of the machined face,also. Larry B.

[johnta1]

John, you are right.
I had forgot about that.
Mixing up with the partial VIN stampings probably.
(crs? )

[60sstuff]

A 65 Survivor that is a Kansas build with the WS above the number.