# 12 bolt...finally



## Too Many Projects (Nov 15, 2008)

I finally picked up the 68 Chevelle 12 bolt yesterday. Some of you may remember when I posted about this a few MONTHS back !! Not only did the seller jack the price up when I got there because he'd gotten a PHONE OFFER but it was still in his car. I paid $200 down and he was supposed to get it out the next weekend. That was 3 months ago. Oh well, 2 60 mile round trips and it's in my shop now....

Oh yeah, tomorrow I'm going to get the rotisserie I bought around the same time. That was delayed because it's 100 miles away and both the seller and I were busy.


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## geeteeohguy (Feb 2, 2008)

Mitch, all you need to do now is tie one hand behind your back, turn off the heat, and get right on it! Instead of Bear Grylles in "Man vs Wild", it'll be "Mitch vs Car!" As you know, you're not the only one out there who's trying to run underwater doing their resto. As the overall character of people in general keeps deteriorating, you just have to work that much harder. Low functioning people that waste other folk's time are a particular pet peeve of mine. Hang in there, it can only go up from here!!


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## Too Many Projects (Nov 15, 2008)

Jeff, I'd call the3 guy every couple weeks and he'd have some new excuse, but, I have it now. I just finished removing the junk upper bushings in preparation for having it sand blasted. The axle itself is near pristine with very little surface rust !!


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## 68gtohawk8369 (Oct 26, 2009)

*12 bolt prices*

Im also in the market for a usable 12 bolt posi for my 68 GTO what can someone expect to pay if they can find one ????


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## 68gtohawk8369 (Oct 26, 2009)

*found a 12 bolt*

I found a 12 bolt from a 1970 chevelle what will need to be done or changed to make it work in my 68 GTO also I would want to change the gear it now has a 410 in it I want 323 or possibly 355 does anyone know what I can expect to pay to change the gear plus factor in a worst case senario like whatever else could possibly need to be replaced any input would be appreciated thanks !!!:cheersforgot to add this is a 3 series is that good or bad????


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## 68gtohawk8369 (Oct 26, 2009)

*12 bolt open rear*

can you put a posi unit in a 12 bolt open rear dont laugh guy's im new to this and need advise thanks im trying to find out if im better off buying a real posi with the wrong gear for my needs and switching the gear or buying an open rear and rebuilding it if possible with a posi unit and new gear the open rear is half the price 400 .00 asking than the posi 800 asking price


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## Too Many Projects (Nov 15, 2008)

68gtohawk8369 said:


> can you put a posi unit in a 12 bolt open rear dont laugh guy's im new to this and need advise thanks im trying to find out if im better off buying a real posi with the wrong gear for my needs and switching the gear or buying an open rear and rebuilding it if possible with a posi unit and new gear the open rear is half the price 400 .00 asking than the posi 800 asking price


$800 for the posi is a good price if it is in good, usable, condition. You already want to change the gears so add about $500 to the price for gears and install kit plus any misc like new axles and outer bearings. Now you're at $1300 to $1800 after a complete rebuild. The open for $400 needs a posi unit and gears plus the possible axles and bearings. A new posi is around $400-500 depending on what you get and the gears and install are the same for either one. You end up at the same cost either way, but the new posi is "new" with a warranty. IF the open axle has gears you could live with, there is a posi conversion available that installs INSIDE the open gear carrier and is about $425. This you could probably do yourself or with a little help, unlike the gear and carrier change that requires special tools and experience. This would be the least expensive route IF the axles and bearings are good. They are something you could replace yourself too and save labor. My 12 bolt has 3:08 gears, which I'm not fond of but will stay for now and I'll put the posi conversion in my carrier myself. I paid $375 for mine and would buy the open for $400 in a heartbeat.


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## 68gtohawk8369 (Oct 26, 2009)

thanks Mitch


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## 68gtohawk8369 (Oct 26, 2009)

Mitch I forgot to ask is installing one from a chevelle a simple bolt in and bleed as long as the drive shaft is the correct lenth or is there much more to it than that and what gear would you preffer? the 410's I think would be way annoying I had an old's with a 390 gear no fun except stop light to stop light im thinking 323's maybe 355's


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## 66tempestGT (Nov 28, 2009)

i dont mean to step on mitch, but i read your post about no responce. you may need a bastard u-joint. also the brake line could possibly be different (the rubber line). you can probably use a combination of the existing fittings and whatever comes on the new one. may not be any difference. other than that i think you just bolt it right in.


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## Too Many Projects (Nov 15, 2008)

68gtohawk8369 said:


> Mitch I forgot to ask is installing one from a chevelle a simple bolt in and bleed as long as the drive shaft is the correct lenth or is there much more to it than that and what gear would you preffer? the 410's I think would be way annoying I had an old's with a 390 gear no fun except stop light to stop light im thinking 323's maybe 355's


Sorry, I didn't see this until now. The axle itself is a bolt in with the exception of the left, upper control arm. Being the housing is larger to accommodate the bigger carrier, the arm will bind on the housing and needs to be ground down for clearance. Chevrolet then spot welded another layer of metal to the arm there to reinforce it for strength. I will be doing this mod to my upper arm when I get it out, if you are interested in seeing it.
As for gears, I think you are on the right track with the 3.XX. Chev gear ratios are slightly different than Pontiacs but there is a 3:31 available that should be a decent compromise unless you plan to tour/travel with it. Then a 3:0X would make more sense.



66tempestGT said:


> i dont mean to step on mitch, but i read your post about no responce. you may need a bastard u-joint. also the brake line could possibly be different (the rubber line). you can probably use a combination of the existing fittings and whatever comes on the new one. may not be any difference. other than that i think you just bolt it right in.


12 bolts did come with 2 different yokes and usually need a special u-joint that matches them up with different driveshafts. I have one in my Chevelle now as the driveshaft came from a 442 that had a smaller u-joint cap than a correct Chevelle would've. I'll get the NAPA number off the box later when I go to the shop.
The brake lines, and all hardware in the brakes themselves are the same. You will want to use the distribution block and correct flex hose for the car, not the axle.


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## heyman (Jan 15, 2010)

is this 68 Chevelle 12 bolt going in a 67 GTO, if so it's an inch wider, will fit fine, but you will lose 1/2 inch on each side in tire clearance


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## Too Many Projects (Nov 15, 2008)

heyman said:


> is this 68 Chevelle 12 bolt going in a 67 GTO, if so it's an inch wider, will fit fine, but you will lose 1/2 inch on each side in tire clearance


Pontiac went to the wider axle in 67 versus Chevelle in 68, so it's actually the correct width.

Nice avatar !! have more pics of that bad boy ???


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## heyman (Jan 15, 2010)

damm did not know that, learn something every day, think there should be in My Photos,


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## Too Many Projects (Nov 15, 2008)

heyman said:


> damm did not know that, learn something every day, think there should be in My Photos,


I didn't either, till I bought this car. I've been a Chevy man for 45 years. There are a number of items on Pontiacs that preceded Chevs, like the throttle cable on my 67. Chev didn't get cables till 69...


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