# '68 GTO engine stamp



## trevorhoare (Jul 31, 2010)

Hello everyone. Just purchased a 68 GTO to work on, and am looking for some advice/support.
Right now, I'm trying to verify matching numbers. The data plate matches the VIN, but I'm having a problem figuring out the block.
On the RH upper part of the block is a 6 digit number stamped followed by the letters YS. This number matches the "Engine Unit No." on my dealer invoice from PHS.
But... according to everything I've read, the VIN should be stamped on the block, and I can't find it. There's nothing where the stamp should be, it's just smooth.
So, since the stamp matches the PHS documentation, is this considered the matching block? 
Anyways, any help would be much appreciated.
Trev


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## Jeff's Classics (Feb 24, 2010)

The YS code is a good start, but to be truly considered "numbers matching" (IMHO) you need to find the VIN derivative. I just got my '68 in March and I've been out of town most of the time since. But...I think it was down by the lower right hand (of the car) side of the block, in the front. It's best to clean the area with degreaser/carb cleaner/brake cleaner, and use a flashlight and maybe a mirror. The stamp isn't very deep into the metal, so even just a little dirt, grease, etc will make the letters disappear from view.
If you can't find it, don't let it spoil the fun of having a great '68 GTO!
Later
Jeff


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## trevorhoare (Jul 31, 2010)

I'll try that. There was some grime there, so hopefully the VIN's underneath once I get that off.
Thanks!
Trev


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## 68greengoat (Sep 15, 2005)

Steel wool works good to clean the area too.... Here's the location of the vin by the timing cover, if there was a question....


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## geeteeohguy (Feb 2, 2008)

If the EUN on the engine matches your dealer invoice, which you said it does, it is definitely the original "born with" motor. No VIN needed.


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## 68greengoat (Sep 15, 2005)

Unless it's been restamped, which has been brought to this forums attention by a member who claims it's a common practice(not sure I believe it's that common). VINs can be restamped too. Check the "cast" date code by the dizzy(not as easy to redo). If everything matches, I would say it's a numbers matching. You have to draw the line somewhere...... Date code the heads too and see if they are '68s.

Also, a '68 YS coded engine should have block casting #9790071(located behind the #8 cylinder). '69 YS engines also used this #.


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