# 71 GTO Engine Found and Running!!



## Raceb8 (Aug 18, 2020)

Hey all!!
This is my first posting here. Last week I finally convinced a family member to sell his '73 Formula Firebird to me as I was looking for a project to start on. I got her home, did the usual tasks to get her running, and she fired right up!! Turns out at some point, a 71 GTO Judge 455 engine was installed. Research into it led me here. Figured I would let everyone here know it's been found, and am open to suggestions as to what I should do with it. The plan is to replace it with a modern LS setup, and figured a new (or possibly original) home could be found here. Right now I'm getting all the schmoo cleaned off and motor mounts replaced so she can drive somewhat more comfortably in the time being. 
C156758 YC is stamped up top, and 21X318978 is stamped down by the timing chain cover if this helps anyone.
Any and all feedback would be appriciated!!


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## pontrc (Mar 18, 2020)

Thanks for takin the time to share the info, not many 71 judges were produced and don’t know how many survived.I know one engine was found by a owner in a jet boat


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## O52 (Jan 27, 2019)

May not be the feedback your looking for, information from the 1971 service manual;

C156758 - EUN/PEN (Engine Unit Number or Production Engine Number)

YC - Engine Code
455 Automatic
325 HP
Big Valve heads, pressed in studs, 8.2 -1 compression
067 camshaft

21X318978 is the car's partial VIN
2 - Pontiac
1 - 1971
X- Kansas City Plant
318978 - Serial Number

Kansas City only built B body cars in 1971. Looks like you have a Catalina/Bonneville/Grand Ville engine
Mild camshaft but not to bad considering the year.


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## Raceb8 (Aug 18, 2020)

Thank you!! I know that 71 Judges are rare but who is going to challenge their great-aunt's story of her car. Certainly not I!! 
I feel better knowing there isn't a GTO out there missing my engine. Maybe I'll keep it in the Formula...if I can get the snorkel hood to shut with an air cleaner installed. Today, pulling out of the parts store, I gave her all the gas pedal could give. The motor seemed quite peppy, having only gaining traction midway through third gear. 
Thanks again for the info!!


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## pontrc (Mar 18, 2020)

I’m glad O52 had his decoder ring handy. If it was me Race I would keep that old 455 in their, you will get a lot more respect from the Pontiac crowd


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## michaelfind (Dec 14, 2018)

Raceb8 said:


> Thank you!! I know that 71 Judges are rare but who is going to challenge their great-aunt's story of her car. Certainly not I!!
> I feel better knowing there isn't a GTO out there missing my engine. Maybe I'll keep it in the Formula...if I can get the snorkel hood to shut with an air cleaner installed. Today, pulling out of the parts store, I gave her all the gas pedal could give. The motor seemed quite peppy, having only gaining traction midway through third gear.
> Thanks again for the info!!


I love the idea of keeping a classic Pontiac motor in that classic Pontiac car!


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## Mine'sa66 (Oct 30, 2019)

Raceb8 said:


> Hey all!!
> This is my first posting here. Last week I finally convinced a family member to sell his '73 Formula Firebird to me as I was looking for a project to start on. I got her home, did the usual tasks to get her running, and she fired right up!! Turns out at some point, a 71 GTO Judge 455 engine was installed. Research into it led me here. Figured I would let everyone here know it's been found, and am open to suggestions as to what I should do with it. The plan is to replace it with a modern LS setup, and figured a new (or possibly original) home could be found here. Right now I'm getting all the schmoo cleaned off and motor mounts replaced so she can drive somewhat more comfortably in the time being.
> C156758 YC is stamped up top, and 21X318978 is stamped down by the timing chain cover if this helps anyone.
> Any and all feedback would be appriciated!!


Since you're looking for opinions, I'll throw my .02 in the ring.
I say keep the Poncho engine!
Your original plan will result in J.A.LS. syndrome.
Just Another LS


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