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lucky13firebird
06-20-2012, 07:18 AM
MY 68 firebird has a pontiac 8.2 that originaly came with a 3.55 gear ratio and now has an unkown brand 3.82 ratio gear set in it from WAAAAYYY back.... like the 90's or even the 80's. My build is severely budgeted, (well not really, just has a cap of 1k a month for it).

My question is, how strong is my rear end? I know the chevy 10 bolt 8.2 is garbage, but I've heard the BOP 8.2 is almost as stout as the 8.5" 12 bolt.... and I've also heard that the 8.5" 10 bolt is a good budget street rear end. See, my dilema is I have a very rare close ratio FORD 3 speed with the original 3 SPEED hurst shifter with linkages and all from a 68 GTO and 66 catalina. It shifts great and is the thoughest tranny I've ever seen (the FORD toploader really is no joke)...

But the 3.82 gearset is killing me in gas and oil changes. I would love to go down to a 3.55 or a 3.33 if my rear end is no good. The other option is of course to buy a TKO600 (the only other tranny i would trust behind the 461 pontiac) and then the overdrive will help me out. But then I would have to part with my beloved $100 junkyard FORD tranny...

I can only afford to change either my rear end or my tranny, but not both. I know for a fact that pontiac used a different rear for the 2.55-3.08 rears and the 3.33-4.11 rears because you can't put a 3.90 (3.82?) gearset into a BOP rearend with a factory 2.80 setup. you'd need to find a 3.31 and up housing.

will I be safe spending money on a TKO600 or will I scatter my rearend all over very soon and then would just buy a 9" with a 3.33 gearset and posi?

Just as a side note, I've been beating on this thing for well over a year and the previous owner has been beating on it for over 10 years and it was the owner before that who installed the 3.90 gearset....

thats 15 years of known dumba$$ery so am i then safe to assume i can throw in a posi and a 3.55 or 3.31 gear and stay happy with it?

Nicks67GTO
06-25-2012, 06:36 AM
I asked this same question over on the Performance Years forum a while back. I was deciding what to do about my rear axle in my 67' GTO. Ive got a 455 and a 5 speed as well. The consensus was that if you're building a stock 400 engine and never going to run slicks you would be fine with the 8.2.

Slicks + Stick + 4.21" stroke = a shredded 8.2 . I opted to go with a 9" and piece things together with deals off ebay. Check out Quick performance out of Iowa. They're a very reputable company. Also 9" stuff is cheaper and there is a FAR better selection of parts.

First Bird
06-29-2012, 07:32 AM
From everything I read before choosing a rearend for my 68 Firebird/455/5-speed I will disagree with the idea that a BOP 8.2 is almost as strong as a GM 8.5. I built and installed a 8.5 GM 10 bolt from a 1973 Nova because I heard they were significantly stronger than the 8.2 and almost as strong as a 12 bolt rear if spec'ed properly (Moser axles, etc).

Skip Fix
06-29-2012, 08:02 AM
FWIW when I raced NMCA stock classes John McWhirter(an original Comp Cams owner) was in my class with a 67 tripower 442 that had an 8.2. The car ran high 11s with a stick. Often he would break mainly the rear and you would get the win. He often would break the gears themselves and started re heat treating them.

68Formula
06-29-2012, 09:07 AM
From what I recall there's a regular 8.2 BOP and there's a Heavy Duty Nodular 4 pinion. Supposedly the 4 pinion is pretty strong, and I believe Sporter is running one in his 455 Bird (non-slicks though). The non-heavy duty is still stronger than the Chevy version, but if that's what you have, probably better to ditch it.