68-70 GTO 10 bolt questions

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65gto
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68-70 GTO 10 bolt questions

Post by 65gto »

Hi,

I have a 65 GTO with a 10 bolt with the code XH, which may actually be HX depending on how you read it. I'm sure its the later and wider housing, and also sure its a 3.55 gear set with the stock 4 pinion posi carrier.

Its been in the car a long time and needs to be replaced or rebuilt. Because its not correct for the car I was initially thinking of selling it and buying a crate 9" or 12 bolt. After pricing out those options I'm back to looking into bringing this rear end up to snuff.

It currently drives fine with only the occasional weird noise on deceleration.

How do I determine exactly what rear I have, and what parts should I use if I wanted to replace the posi and make it into a good long term rear end. What kind of power can these safely handle if used carefully?

At the moment I am not drag racing the car. Currently has about a 500HP 455 in it with an Autogear M22W 4 speed trans and a 26" tire.

Thanks in advance for any help with this.
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monzaz
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Re: 68-70 GTO 10 bolt questions

Post by monzaz »

Ok well 65 GTO here is the deal-
The 10 bolt 8.2 can handle plenty of power when rebuild back into newer specs again.
Stick shift cars are always harder on drive line parts. Reason as the drive has total control to lay down the power gently or neck snapping hard.
IF you are not going to the track the Pontiac and most ALL rear ends will hold up quite well when maintained and or rebuilt to new again .
So many 65-72 Muscle car era rears are popped in and out of car so many times and never even have the oil checked..lol Then they blow and think they need a bigger stronger rear when all they needed was a re-bearing and freshening up with shimming.

Could be the posi unit needing a going through / or could just beed bearings and things are a bit sloppy as stated above paragraph.

Post some pictures on the sight and give any casting number you find on the cast center section. AND where its location is. Jim
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65gto
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Re: 68-70 GTO 10 bolt questions

Post by 65gto »

Thanks Jim,

I'm thinking seriously about replacing the rear end with a ford 9" as I'm told that the 8.2 will not hold up to any serious power. The car will be drag raced occasionally, but 98% of its use will be on the street. Turns out the noises I was hearing were from my dang Reverb, so the rear is currently not making any noises, however the posi is worn. It does have the HD style 4 pinion carrier, I remember that from the last time the cover was off. If I lift the car up now I can spin one wheel and the other stays still, I think previously the other would spin the same direction. I also don't think we have a good two stripe burnout anymore so the posi is likely very tired. It has been under the car since 92, so I guess thats acceptable.

In my shoes, which way would you go? Can you supply the parts I need to freshen it up if I wanted to? The rear end is not stock for the car, so I'm not losing any originality by switching it out, just spending more $$ which I would prefer not to do.
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monzaz
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Re: 68-70 GTO 10 bolt questions

Post by monzaz »

98% street stay with your stock rear...

I do not like 9" Fords anyway. Stock 9" is a boat anchor in our shop...If we were to do one it would have the pro center not the 1.313 pinion.

Yes we have the parts here PM me for prices. Master rebuild kit - Posi unit ring and pinion probably good. IF you like your ratio..

Axle bearings and seal to if you like.

Jim
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65gto
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Re: 68-70 GTO 10 bolt questions

Post by 65gto »

PM sent.
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