camrat68

I tried running a search for rear axle dimensions here and at a few places on the net that build rearends for first gen Camaro's-No Luck.
I'm looking to purchase a 12 bolt posi locally that is supposed to have 3.55 gears and a "PQ" code. Running the codes though, it came up as a 3.55 12 bolt NON-posi (67).
This is the second 12 bolt rear that I've looked at. The first turned out to be from a 71 nad I was lucky enough to have the gentleman refund my money.(Very rare!) The problem was that I didn't know the correct rear end dimensions. I currently have a 10 bolt posi in there now from a 74 Nova, and measuring the housing is pretty difficult. I also have the original 10 bolt out of the car, but don't know if the dimensions are the same from 10 to 12 bolt on a 1968 Camaro.
Any help or suggestions would be appreciated before I look at the 12 bolt on 12-14-03.
THANKS!

MTmace

Are you really looking for the dimensions? Or are you looking to see what 12 bolt rear end will bolt right into your 68?

I had the same question, take a look at the following thread:

http://web.camaross.com/forums/showt...hreadid=196696

There you will find a list of cars that will fit your car.

MTmace

camrat68

Yeah, I was actually trying to get the dimensions. I've seen the list of donor cars, and currently have an 8 1/2'' 10 bolt out of a Nova in there now. Mostly I was trying to get as much information as possible so that I could verify that this rear is what it claims to be-before I handed over the cash.
After thinking about it though, I realised that the axle flange to axle flange distance would have to be the same as my stock 10bolt non-locking rear, as well as the flange to spring perch distance. The only difference should be in the depth of the spring perch mounts from mono to multi leaf springs. The only "PQ" coded rear was in 1967(3.55 12-bolt non-locking) and the owner claims to have run the numbers and believes it to be from a '68 and says it's definitely a posi.
I guess the only way to know for sure would be to measure my old housing and then crack open the 12 bolt and count teeth on the ring and pinion gears, and look for the locking carrier.
Thanks for the reply MTmace, and I'll let ya'll know how it works out!

Jeff H

Someone may have upgraded that PQ non-posi to a posi at some point in time. All you need is the posi unit so it's not a difficult thing to do. You should be able to turn the rear axle and count the number of times the driveshaft yoke goes around to complete one full rotation of the axle(tire). That will tell you which gears are really in the housing.

camrat68

OK, as it turns out, this rear end isn't going to work out for me.
Stock 10 bolt rear dimensions..
60 1/4" from wheel mtg surface to wheel mtg surface
53" from brake backing plate to bkg plate
40" from INSIDE edges of spring perches
4" from OUTSIDE edge of spring perches to brake backing plate
2-2 1/8" for spring perch depth-MULTI leaf
1" for spring perch depth-MONO leaf

Now, when I talk about the inside and outside edges of the spring perches, I mean right where the spring sits in the perch.
So if you measured from your backing plate to the outside edge of your leaf spring, it would be 4". And if you measured from the inside edge of your passenger's side leaf spring to the inside edge of your driver's side leaf spring, it would be 40".
These measurements were taken from my OEM 10 bolt, my 10 bolt posi(74 Nova), and confirmed by measuring a 12 bolt posi in someone else's '68 Camaro. Maybe this picture would make it easier to understand..
http://www.msnusers.com/HiPerfCapric...to&PhotoID=137

So now I know. BTW, I couldn't use this housing because some one had moved the spring perches to fit this housing into a 2nd Gen Camaro-42 3/4" from INSIDE edges of spring perches. It's too bad, he only wanted $1000 for it and it was a good posi with 3.50 gears. I guess that the housing for a 2nd Gen is wider between wheel mtg surfaces than a 1st Gen, and he wanted to run stock wheels.