Serial number mystery

The engine code on my 76 Buick Electra Limited, who is built in Flint, has engine code Y.
And as far as I can find out, there wasn’t any engine code Y in 76.
The serial number is 4X39Y6H448851
Is there anybody who has an answer about this.
My Buick.
http://spirit-of-america.biz/images/DCP_3684.jpg

What do you think should or shouldn't be based on the Y?

What do you think should or shouldn't be based on the Y?
I have a 455 cid engine in my car and my 76 Buick shop manual says it should have been a T in the serial number,not the Y that I have, but I suppose the shop manual is not correct.

You are right there is no y code engine in 76, t is the 455. Where did you get this number

You are right there is no y code engine in 76, t is the 455. Where did you get this number
It's on the chassie number plate in the front window and on the title.

Google for a Buick club that can decode that vin, maybe something is awry, could be it was stolen and replated years ago ( lol)

Run a CarFax report on that VIN and see the history on the car.

Hi
This 76 Electra on eBay has also and Y engine code in the serial number, same as me.
Link (http://cgi.ebay.com/ebaymotors/Buick-Buick-1976-Buick-Limited_W0QQcmdZViewItemQQcategoryZ6144QQitemZ4612 983661QQrdZ1QQsspagenameZWDVW)
The American car club of Norway has tons of literature, but they couldn’t figure why I have a Y and should have a T in the serial number, according to Buick literature.:confused:

Was the engine changed, but my research says the limiteds all had 455's.

Was the engine changed, but my research says the limiteds all had 455's.
Yes ,it is a 455,but the confusion from my side, is that there is not any engines code Y in the 76 Buick service manual.
And I have a Y engine code in my serial number.
But my conclusion is that shop manual is wrong or incomplete.

I found a Buick info site that does not list a Y engine till the 80's which was the 307.