# Decoding GM Engine Help Needed



## FireFox3434 (Jan 3, 2014)

Hi I have A engine in my GTO and wanted to see if anyone can help me decode it to see if possible original or not?

Engine code on block on passenger side.

C 446785 WR

I have a 1968 GTO with a manual transmission.

Any Help is appreciated.

Tom


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## Matthew (Feb 11, 2011)

Tom, this site should help you: Pontiac Power

In order to tell if it is the original engine, you will need to look at the Block VIN number. 

Matt


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## BearGFR (Aug 25, 2008)

If you're sure of that "WR", then according to the sites I've checked it's not the original engine. In 1968, WR was only used on 350's - and your GTO would have had a 400. 

Check the date code (4 characters - 1 alpha followed by 3 numerics, top rear of block, near the distributor hole) - easier to see with a good light and a mirror. The date code will ID the model year. The model year combined with the "WR" will tell us exactly what you've got there.

Bear


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