# Crankshaft question



## Ohio66GTO (May 19, 2014)

I’m looking to start the engine rebuild on my 65 block I picked up. The engine was seized from sitting when I got it and I was finally able to break it loose and disassemble it. My question is weather I should just have a regrind and polish of the original crank or spend the money and get the forged crank? I’m not going to be racing the car so just wondering what everyone thinks about using the original one. New one is in the $600.00-$700.00 range and the regrind and polish is about $180.00.


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## bigD (Jul 21, 2016)

I'd go with a forged stroker assembly, & 6X heads. Easy 400hp/500 torque, on pump gas, with a 4.25 stroke assembly. 

https://butlerperformance.com/i-245...-389-block-4-250str.html?ref=category:1234862

But, if you really don't want that much power, don't wanna spend that much, AND your crank can be used that cheap, then there's pretty much only one choice. No problem makin 300hp+, with a pump gas stock stroke engine. The factory 4-barrel GTO 389 was factory rated at 335hp. NHRA factors it at 300hp. 

EngineSpecs

There are obviously lots of things to consider, like which heads, how much compression, cam, intake, carb, etc.

Also depends on how original you want the engine compartment to look.


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## Ohio66GTO (May 19, 2014)

Yeah, I’m going for the more stock/original look. Have a period correct block and heads. I have the original numbers matching tri-power setup. I am just seeing what people think about using a crank that is 54 years old. I don’t think I need a forged crank but I like the piece of mind having it. I see Kauffman has a stock steel crank made by Ohio for $325. I’d be happy using the original but just wondering if it will be a weak point in the assembly being so old or will it be just as good as the new Ohio one once I get the regrind and polish done? First time building an engine so maybe I’m overthinking it.


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## PontiacJim (Dec 29, 2012)

Ohio66GTO said:


> Yeah, I’m going for the more stock/original look. Have a period correct block and heads. I have the original numbers matching tri-power setup. I am just seeing what people think about using a crank that is 54 years old. I don’t think I need a forged crank but I like the piece of mind having it. I see Kauffman has a stock steel crank made by Ohio for $325. I’d be happy using the original but just wondering if it will be a weak point in the assembly being so old or will it be just as good as the new Ohio one once I get the regrind and polish done? First time building an engine so maybe I’m overthinking it.



Should not be a problem, especially with a stock application. Using a stock crank will ensure it is correct from the get-go. Pontiac cranks are pretty stout. Your machine shop should first vat (clean) the crank, then magnaflux it for any cracks, and check for straightness. If all passes, then they will mic the journals and let you know how much the crank needs turning.

I would not purchase a new crank unless the factory crank proved to be bad. You will not need forged even if you do buy a "new" crank unless you plan on severe use or going big stroker.

What I do recommend replacing is the factory cast connecting rods. They too are failry rugged, but they are cast and you don't know how hard they have been run up. Even if you rebuild them and had the upgraded ARP bolts installed, you still could have a rod go bad. For the price of a new set of forged I-beam connecting rods, you get the stronger forgings & better rod bolts. You do not need the H-beams. The I-beams are like factory and will hold up just fine for your application. https://butlerperformance.com/i-316...25-2-250-pontiac-rj.html?ref=category:1234812 Jegs also has them and may offer free shipping. Summit for some reason does not offer them, but am sure if you email, they will get them. They offer free shipping over $100.


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## Ohio66GTO (May 19, 2014)

Thanks for the info guys. I’m going to use the original one. I just wanted to get some experienced opinions before putting the money into it and having problems later.


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## DustyOldGTO (Jun 26, 2019)

Good information and advice. I'm about to start down the same road with my 65 389.
It has been run hard - new rods are something to think about.


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