At the moment my car has the original 8.2 non-posi rear in it. I am putting a 454 chevy in my car and want to know what u guys think i can do it make this rear hold up. I was looking at a full spool for the rear but dont know how good that would be on cornering. Are the spools or carriers, axles and other things the same on a pontiac as they are 8.2 chevy rear. Plan on using a 3.73-4.11 ratio and my car is a 4-speed. thanks, eric
I agree with Tom. But there's an alternative: Find a 2nd gen Trans Am 8.5" 10-bolt with the larger forged axles. You'll need to do some blacksmithing to fit the spring perches, but the swap is covered extensively in the FAQ on this site.
Ive got the second gen in mine. The cost of the second gen is cheaper and easier to find then a 67-9 12 bolt {.02}. A plasma cutter is the way to go on the perches. G.L. Bill
Hey 400+, How much wider is the sec gen rear than the stock 8.2? A friend told me 3/4" total, then someone else told me 2". Sec gen covers 70 thru 79? 8.5 right?
You could also look for a 8.5 rear from a 73-79 Nova. They bolt right in without having to cut the perches. They are 1" shorter than the Firebird rear but the spring perches are perfect and most are already set up for multileafs. I just finished installing an 8.5 from a 79 Nova with posi and it fit in no problem. You will have to account for the 1/2" difference on either side if you have aftermarket wheels but the Rallys fit with no rubbing at all.
kingbird, Did you have to use a diffeent u=joint? I thought the chev was different. Also, will you have to adjust your drive shaft? I thought someone said the pinion stuck out farther on the chev than the pont.
IMO The original rear end should stand up to just about any engine you put in the car. Build it right, build it tight. I have run 450HP with stock 10 bolt BOP rears without a problem. Pick up an Eaton or Auburn posi unit to make it posi and you are good to go. Jegs and Summit have all the parts you need. Keep in mind it's a tricky job and you should have an experienced hand looking over your shoulder when assembling.
Look about half way down the page at "68 Rearend Swap"
I have not tried this - I'm after something a little more difficult - but it's not an uncommon thing to try.
... and, yes, the 10 bolt stock rear end will take horsepower, but the 12-bolt and the 8.5 were both designed to handle the higher torque of the 455 HO. (The 12-Bolt was put into the 1970 GTO behind the 500 Ft-Lb. 455, and in the 1971/72 TA behind the 455 HO.)
Firebob, I did have to change the U-joint but I just told the guy who was rebuilding the rear what it was going into and he changed the u-joint. As far as the drive shaft you will have to have 1" cut off. To me that seems a lot safer than cutting and rewelding perches and also a lot cheaper. I also did this swap on a 67 Camaro and to have the driveshaft measured,cut and balanced was $120 at a local differential shop.
i'm running a 12 bolt in my 68 coupe and the only thing i had to replace was the rear yoke (small u-joint). No mods to the driveshaft and no u-joint replacements required.
the 12 bolt rear was already installed in my 68 coupe when i bought it. According to previous owner, the 12 bolt and shaft were from a 68 or 69 big block Camaro running a 4-speed muncie. If you do the 12 bolt, make sure you know what series carrier you have. a 3 series will take up to a 3.73 gear. you would need a 4 series for a 4.10. As long as you know what carrier you're running, Richmond Gear carries the thick ring and pinion gear set for the 3 series carrier, if your stock gear is, say, 3.23, you'll need the thick 4.10 gears for your 3 series carrier.
It's quite possible with an all-Camaro drive line like you have, the drive shaft would not need to be shortened. In the case of putting the Camaro 12-bolt into a Firebird with a Pontiac motor, the driveshaft would have to be shortened.
Well it sounds like a fairly straight forward swap after you know all the things that need to be done. Now that I consider all the mods and cost involved I'm not sure it would be the right choice for me. Think I'll just upgrade my original. Not so much time involved.
Robert, It'll hold up if you build it correctly. My 428(torquey) with a power shot Nitrous Oxide kit made 50 trips to the track and then retired to the street. The guy that bought it from me still drives it with no problems with the BOP ten bolt. I would get on the phone with Summit and order the Eaton carrier and the complete installation and bearing kits. There are no C clips in the BOP ten bolts so you are already better than the Chevy rear ends in that respect. If you want to spring for plane fare and lodging for two I'll build it for you.
Firebob! Sorry I didnt get back to you on your question. Shut down for the week out of town. Came back for a visition. Sounds like you have it taken care of. Bill
