[71SportRagtop]

I have a one legger rear in my 68 Firebird. My buddy has a 68 Camaro with a factory 10 bolt 8.2 rear with a posi and 3:36 gears. He's swapping it out for a 12 bolt rear he scored off of craigslist and he told me I have first dibs on his 3:36 rear before it goes to craigslist.

Is this a direct swap? I would love to have a 3:36 posi rear in my car but I don't want too much hack work.

Any feedback?

[bsblguy]

I had a 68 bird that i had to replace axles in and they are same as camaro. I think it will bolt right in.

[b-man]

You will need an adapter U-joint, other than that a bolt-in.

[Cammer-6]

8.2 Cheby is a pretty weak unit

[RAJ7395]

Pontiac rearend is 1" wider than the Chevy.

[frankyboy455]

Originally Posted by RAJ7395

Pontiac rearend is 1" wider than the Chevy.

Originally Posted by Cammer-6

8.2 Cheby is a pretty weak unit

X2 on those statements

Originally Posted by bsblguy

I had a 68 bird that i had to replace axles in and they are same as camaro. I think it will bolt right in.

Chevy axles are C-Clip style (you have to remove cover, then remove pin, then remove c-clips to remove axles)
Pontiac axles are externally bolted to the tube via 4 bolts. No need to remove cover. Bearing is pressed on axle while Chevy has bearing in tube.

[71SportRagtop]

OK so I'm not worried about the strength of the Chevy unit. My car was originally a 6 cyl Sprint car that now has a mildly built 400 with a Muncie 4 speed. The 6 cyl rear has held up to my weekend cruising so I'd expect a Chevy posi rear to hold up also...right?

My main concern is with the driveshaft. I figured the rears would be pretty direct bolt ins. If I am installing this rear and I have to customize my driveshaft or buy a new one then it might not be worth my while.

I've been on the search for a correct 67-69 Firebird posi rear with no luck. I can buy a complete new posi unit with gears and install kit for about $700.00. Plus I'm figuring about $300 in labor and I'm also thinking about $100.00 in new bearings and axles seals and I'm at about $1100.00. My buddy will let me have his 3:36 rear for $300.00. Even if I have $200 in extra parts or unknowns, I would come out $600.00 ahead.

I just don't want any major or hidden issues. I'm doing my rear, re-doing my top end, and installing a 400 hood this winter and I do NOT want any obstacles that would keep this car off the road for cruising season.

[limejudge69]

The Camaro rear will be fine for what you are doing. As B-Man said you will need a conversion u-joint. The Chevy yoke is smaller than the Pontiac yoke. It's no big deal. I have used the Neapco part # 3-3130 with good results. Advance Auto has them for around $12.

[Firebob]

Another option is the Powertrax unit from Richmond. Replaces your spider gears. Just drops in. No messing around with the R&P. About 3hrs to install(if you're as slow as I am). I think they run about $450 from Summit. Alot easier than R&Ring the whole rear end.

[Cammer-6]

Originally Posted by 71SportRagtop

OK so I'm not worried about the strength of the Chevy unit. My car was originally a 6 cyl Sprint car that now has a mildly built 400 with a Muncie 4 speed. The 6 cyl rear has held up to my weekend cruising so I'd expect a Chevy posi rear to hold up also...right?

My main concern is with the driveshaft. I figured the rears would be pretty direct bolt ins. If I am installing this rear and I have to customize my driveshaft or buy a new one then it might not be worth my while.

I've been on the search for a correct 67-69 Firebird posi rear with no luck. I can buy a complete new posi unit with gears and install kit for about $700.00. Plus I'm figuring about $300 in labor and I'm also thinking about $100.00 in new bearings and axles seals and I'm at about $1100.00. My buddy will let me have his 3:36 rear for $300.00. Even if I have $200 in extra parts or unknowns, I would come out $600.00 ahead.

I just don't want any major or hidden issues. I'm doing my rear, re-doing my top end, and installing a 400 hood this winter and I do NOT want any obstacles that would keep this car off the road for cruising season.

Trying to figure out your logic here
There is no "6 cyl" rear.
Same rear as the 400 unless you got the "N" nodular HD safe T track,which yes could be had even with a 6 cyl.
8.2 Cheby rear was weaker than any of the Pontiac 8.2s.
Maybe your best bet is to find an 8.2 Pontiac 336 or 355 4 pinion and add a posi unit to it,or as I first mentioned get a spider gear replacement to make it limited slip.Look in the performance section for the new replacement unit that doesnt require resetting R&P.
If youre car was a Sprint and 4 speed it should have been a 3.55 rear already.

[71SportRagtop]

Originally Posted by Cammer-6

Trying to figure out your logic here
There is no "6 cyl" rear.
Same rear as the 400 unless you got the "N" nodular HD safe T track,which yes could be had even with a 6 cyl.
8.2 Cheby rear was weaker than any of the Pontiac 8.2s.
Maybe your best bet is to find an 8.2 Pontiac 336 or 355 4 pinion and add a posi unit to it,or as I first mentioned get a spider gear replacement to make it limited slip.Look in the performance section for the new replacement unit that doesnt require resetting R&P.
If youre car was a Sprint and 4 speed it should have been a 3.55 rear already.

Ok let me clarify. My car was originally a 6 cyl car. It was NOT originally a 4 speed. My understanding is that it was a 6 cyl overhead cam motor with an automatic trans. I don't know if that makes it a Sprint or not. I admit my knowledge of the Sprint cars is limited.

The previous owner converted the car to a 400 with a 4 speed but never swapped out rears. So in my head the original rear is the weak point. I know that it's NOT a posi but I never officially checked the gear ratio. The gears in the car now are not that aggressive. I know the trick of jacking up the rear wheels and spinning the tire while counting driveshaft rotations, but I never bothered because it has always been my desire to convert the rear to positraction. Since it's a weekend cruiser only I'd be OK with a set of gears such as 3:55. I'm not worried about cruising RPM's. My feeling is that with the 4 speed and 3:55 gears the car would be a lot more fun to drive.

I know that my best bet is to find a correct 67-69 Firebird 8.2 posi rear and swap it out but they're not out there. I've been searching for months and haven't found anything. Some guys have rears but the cost of the rear plus shipping something that large comes to more money than just buying a whole posi/gear conversion kit. But that $1100 price is a little salty.

[Cammer-6]

I wish I had even half the 355 posis back I sold for under $200.
Those days are gone.......
get under your car and find the code for rear
it should be next to the brake line clip on the axle tube on left(drivers) side.
standard a ratio for a Sprint auto was 323,which was a 2 pinion

[ponjohn]

Originally Posted by RAJ7395

Pontiac rearend is 1" wider than the Chevy.

For the same car?

[Baron Von Zeppelin]

For $300 you Can't go wrong - especially with a known functioning unit in good order.
If something goes a different route eventually - sell it and split any profit with the friend.
It should resale for about double that.

You Really should jack your car up first and verify the gear (try to find the code too).
Your rear "may" have been swapped during the life of the car - or the gear set changed.
Best to verify physical ratio more so than the code.

What would be a kick in the pants is to change out the rear for the exact same ratio.
You'd gain the posi aspect - but it doesn't sound like a racer or a burn out king.

You could already have anything from 2.73 to 3.55

On an open rear - in most cases -
you rotate the tire 1 exact revolution.
Diligently take count of pinion rotations.
Then multiply that number by 2.

1.5 'ish turns would be 2.92 - 3.08 zone

[71SportRagtop]

OK so I did both the physical tire rotation check and also checked the codes on the axle. Based on what Baron says, I have a 3:08 open rear. My axle/driveshaft rotations X2 came to 3 and my axle code is an XE. I googled 68 Firebird axle codes and it says that XE is a 3:08 open rear.

Here's my issue. The car I sold 2 years ago to buy my Firebird was a 72 Challenger with a 1969 440 6 pack motor along with a 4 speed and a set of 4:10 gears. It was a LOT of car. I ABSOLUTELY love my 68 Firebird and plan on keeping it forever but I'm desperate for some additional seat of the pants acceleration. My basically stock 68 400 along with a 4 speed and3:08 gears is just too humdrum. Frankly, I almost would be OK running a 3:90 gear at this point.

[limejudge69]

The 3.36 gear may be what you're looking for. It will definitely improve your out of the hole acceleration, but won't be so steep that you're buzzing the motor on the highway. It's your cheapest option right now and you can always go with deeper gears if you feel the need to. I have a 67 Bird and I installed 3.73's a few yrs ago. They are fun but are a little steeper than I would like sometimes. I have considered swapping them to 3.23 or 3.42 someday.

[RAJ7395]

Had this one sold to a friend last year but he decided to go with a 12 bolt instead.

$1500.00

1969 ZH 3.55

Nodular Iron housing (original GM)
Forged axles (original GM)
New axle bearings and seals
New eaton carrier with carbon fiber clutches and 800# preload springs
New carrier bearings
New richmond 3.55 ring and pinion
New stainless hard lines
New rubber body to housing flex line
New drums
New brake cylinders
New brake pads
New brake springs, levers, pins, etc.
New stainless e-brake cables
Filled with GM gear lube with posi additive

Bolt in and go!

[71SportRagtop]

Originally Posted by RAJ7395

Had this one sold to a friend last year but he decided to go with a 12 bolt instead.

$1500.00

1969 ZH 3.55

Nodular Iron housing (original GM)
Forged axles (original GM)
New axle bearings and seals
New eaton carrier with corbon fiber clutches and 800# preload springs
New carrier bearings
New richmond 3.55 ring and pinion
New stainless hard lines
New rubber body to housing flex line
New drums
New brake cylinders
New brake pads
New brake springs, levers, pins, etc.
New stainless e-brake cables
Filled with GM gear lube with posi additive

Bolt in and go!

That's a killer rear but I'm thinking that the rear and shipping is gonna put it out of my price range. I was hoping to spend $1000.00 or less.

[RAJ7395]

Ponjohn- Yes the 69 8.2 Firebird rear end is 1" wider than the 8.2 Chevy camaro. This is due to the Pontiac "Wide Track" marketing.

[RAJ7395]

I hear you. However, when you add up the true cost of rebuilding a chevy 8.2 into what you want, I'm confident that you'll be at or above what I'm asking for this one and it won't be as strong. FWIW - I've got close to $3000 in this one.