I've searched until I am blue in the face and my eyes are blurry. I have 2 questions that I hope someone can answer about this weird year for the 8.2. 1. The GS400 and Sport Wagon heavy duty axle is different than the run of the mill Skylark rear. I know the axles are larger along with bearings and seals. Does anyone know if this housing got the "N" nodular iron treatment or is it the more common and weaker Grey Iron? 2. I think most of these rears used 7/16" ring gear bolts right hand thread. Would a 2 or 4 pinion Pontiac Super Trac Posi made for the right carrier series (2.93 gear) and 7/16" bolts (but LH thread) work in the Buick rear? I'm considering upgrading the internals of my original open rear, retain the stock gear, and want something to last if I decide to build the motor and occasionally head to the track with slicks. I might have a line on one of these carriers but would like to know before I commit. I also found a post by member Fireball who stated his 2.93 67 rear had a 4 pinion posi. Most Poncho guys weren't aware the 2.93, 3.08, and 3.23 could have a 4 pinion posi carrier. Thanks in advance,
I wouldn't bother with a 4-pinion unit. I've seen plenty of them grenaded without too much abuse. Yes,ponchos did have them too. There are no replacement parts to fix one,if you break it. They were better than the 2-pinion,but they can't handle that much more,and were never intended for today's power. A column-shifted 70 455,running 12:50's,spit two of them out at the track,and one at a traffic light.
Thank you Brian, I know you have had a good bit of experience with building rears. Thanks for the response.
The original 8.2" rearend from my '67 GS400 has a 2.93 4-pinion posi. Because I race my '67 regularly I removed that original rearend for safe keeping and replaced it with a '67 Pontiac 8.2" 2-pinion 3.55 posi that was in a '67 GTO parts car that someone gave us. That posi stopped working soon after I installed it in the car so it was repaired in about 1996 by Ray Moticka (spelling?) and is still working today. Those original 1967 GM 3.55 years survived until 2002 when I turned a corner at about 10 mph and POW!! It broke several teeth from both the ring and pinion. I bought a set of 3.55 relacement gears and have not had any more trouble. Keep in mind that this rearend has endured about 350 passes at the track, all with sticky tires, with 60' times of 1.66-1.74 and generally runs 7.60s-7.70s in the 1/8 and 12-teens in the 124 mile with best ever of 7.5/11.8. No issues from the rearend unless I don't get them both in the water is at the track. Being an automatic transmission helps it survive in my opinion. At this power level I suspect the stock Pontiac 8.2" will live forever in my all-iron stock appearing '67 GS.
