# Numbers on my GTO Engine



## SOCMedic (Dec 31, 2014)

Ok, so I finally got the grime cleaned off the engine and I found out it is not a 1967 engine which is ok I guess! I am just trying to figure out what it IS!

The numbers are as follows...

A282
5M
87790
32-8
7K3
48988

That is all I could find. Any insight would be amazing, I am looking to start my rebuild next week so I would like to order parts for it, let me know what you think/advise! I really appreciate all the help this far!

Chris


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## geeteeohguy (Feb 2, 2008)

I think you left out a '1' in the casting number. Should be '481988'. There are no '48988' blocks. A282 means it was cast on Jan 28, 1972. The casting number of 481988 is for a '70-'74 Pontiac 400. So you have a '72 Pontiac 400. The 7k3 heads are also for a '72 400, so they are most likely original to that engine. The 7k3's have big valves and are 96cc, so they are pump gas friendly. Not bad at all. So, you have a 250HP 1972 400cid engine. All in all, a good deal. The '72 and ealier blocks are known for their high nickel content and are super strong, durable blocks. You have a great base engine to work with here. It could have been a lot worse!!!


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## SOCMedic (Dec 31, 2014)

I did leave out a "1"! Sorry about that! Great, I am glad to know what I have, now I just need to get a kit to rebuild it so I can take the block to a machine shop to get it bored, cleaned and honed. Is there a kit that you would recommend? Would you piece one together? I am not worried about anything fancy, just want to have fun with it! Thanks so much!

Chris


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## ALKYGTO (Mar 29, 2010)

Before you "buy a kit" talk to your machine shop. Not only can they possibly recommend a kit but could get you a wholesaler discount. Also make sure they have real experience with Pontiacs, these engines do have their own piculiarities.


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## PontiacJim (Dec 29, 2012)

The '72 engine is a great engine. That was what I had in my '68 Lemans before going with the current 455 build. It is 8.2 compression which is pump friendly gas. I ran the cheap 87 octane in mine. Here is where the Competition Cams work well. I used the XE274 cam kit. Pulled like a freight train up to about 5400 RPM's and then power just falls off.

Had another one in one of my GTO's in my youth. Factory stock. It too pulled extremely well even with the lowered compression.:thumbsup:


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## geeteeohguy (Feb 2, 2008)

Exactly. IMO, I wouldn't 'kit' this engine. I'd do a stock rebuild using the crank you have, and the heads you have, with an XE268 or XE274 cam, depending on rear gear ratio. 268 if you have 3.08-3.36 rear gears, the 274 for a 3.55-3.90 geared car. The one thing I would do is buy a set of the cheap aftermarket connecting rods. Use flat-top pistons, and have the block 'zero-decked' while in the machine shop for your piston/rod combo. You will end up with a reliable, economical, powerful, pump-gas friendly engine you can put 100,000 miles on or more with no worries.


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## SOCMedic (Dec 31, 2014)

Ok, we'll tear down starts Monday, I'll post pictures then, once I get it torn down its off to the machine shop and I begin the body work! Which is my favorite part, I'd rather be doing metal work and paint than working on an engine(but I think it due to my lack of experience which I am trying to cure with this build).


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