# 69 12 bolt chevy diff into 67 gto 4 speed



## mbspeed (Sep 25, 2012)

Hi Guys what parts will I need to install 12 bolt diff from a 69 chevelle into my 67 GTO 4 speed I have the drive shaft from the chevelle it had the same 4 speed any help or info would be helpful


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## jetstang (Nov 5, 2008)

That rear is 5/8" wider each side than the 66/67 GTO, so you have to have bigger offsets or stock rims. I use the 66/67 rears in my 70 to get the narrower rear end. Driveshaft should work, but tires may hit fenders. Best of luck.


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## mbspeed (Sep 25, 2012)

jetstang said:


> That rear is 5/8" wider each side than the 66/67 GTO, so you have to have bigger offsets or stock rims. I use the 66/67 rears in my 70 to get the narrower rear end. Driveshaft should work, but tires may hit fenders. Best of luck.


I have 15 '' rims on gto now that makes it worse


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## ALKYGTO (Mar 29, 2010)

Consider maybe trading for the correct year.

Or run the offset wheels. 

Do you have over 5/8" clearance now? I would say minimum should be 1/2" or 5/8" after you install the new rear so you should have at least 1 1/8" per side now or you'll chance rubbing. 

You could "roll" the fenders to gain additional clearance. Many will "poo poo" this idea but if done right it will not damage your paint and be virtually unnoticeable. 

So I would measure first and then decide if you don't have enough clearance to-
*1*. Trade the rear.
*2*. Offset wheels. 
*3*. Roll or clearance fenders.
*4*. Keep your stock rear and upgrade the axles, diff and gears to be damn near as stout as a stock 12 bolt. Remember......stock 12 bolt Chevy's have their weak points too.


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## BearGFR (Aug 25, 2008)

ALKYGTO said:


> ...You could "roll" the fenders to gain additional clearance...


Alky, your fenders must be better than mine. Mine don't roll worth beans. They just sort of rock back and forth on the ground... :rofl:

Bear


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## 68GTO4004Spd (Jun 19, 2008)

I believe you will need a specialized u-joint that goes from Chevy to Pontiac. Ames sells them, but you can probably get them anywhere


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## leeklm (Mar 11, 2012)

I have a 71 12 bolt in my 66 so should be the same. I run 265/60/15 and have used the 7" & 8" rallye one wheels. I forget the exact offset, but they are the ralleys that Ames a d summit sell, so you could look up the offsets offered in those wheels. I am thinking the 7 wheel is a 4" offset and the 8" is a 5" offset.

Sent from AutoGuide.com Free App


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## mbspeed (Sep 25, 2012)

leeklm said:


> I have a 71 12 bolt in my 66 so should be the same. I run 265/60/15 and have used the 7" & 8" rallye one wheels. I forget the exact offset, but they are the ralleys that Ames a d summit sell, so you could look up the offsets offered in those wheels. I am thinking the 7 wheel is a 4" offset and the 8" is a 5" offset.
> 
> Sent from AutoGuide.com Free App


thanks guys


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