# 66 GTO Engine Codes?



## APRAIZR (Jul 27, 2009)

Hello! I'm new and need your help.

I am attempting to ID the original engine that came in a 66 GTO. The original has been replaced by a modified 455 that powers a very nice restomod. There appears to be no two-letter Engine Code on the Data Plate.

What's next?


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## 05GTO (Oct 6, 2004)

The data plate does not include a code for the engine in 66, to find the original 389 engine you could order the build sheet and billing history from this website; PHS Historic Services

The casting number for 66 is located on the machined pad under the distributor and should be 9778789 along with the date code. The letter code will be on the front passenger side of the block under the head, here are the codes;
Manual trannys are;
WS 360hp, WT 335hp, WV 360hp, WW 335hp and XS 360hp; 

Auto trannys are;
XE 335hp, YR 360hp and YS 335hp. 

GTO heads are cast on the center exhaust ports and should be 093,


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## APRAIZR (Jul 27, 2009)

Randy:

Thank you very much! I'm on it.


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