What can't be upgraded into any 8.2 is support in the pinion area. Yes, one can buy an LPW or T/A Performance rear cover to preload the caps... add stabilty to the bearing caps, but the small pinion is still trying to raise up upon heavy torque loading, esp with suspension hooking up slicks. Higher torque manual trans combo's will often tear up an 8.2 first, while foot braked auto cars will soften the blow some (torque convertor) & last longer. I've picked up the pieces from a ton of blown up bolt-in axle 8.2 rearends, but without knowing whether the pinion was loose, one can't always say why the rear failed.
Have posted the following before, but few use the search function & sometimes it does not work...
Some history on GM 10 bolt rearends...
'64-66 Pontiac used cast gray iron 8.2 hsgs with 2 converging ribs per side. Buick used cast gray iron 8.2 housing with single rib per side. Lot of Olds A-bodys received the Buick 8.2 r/e as well. Pontiac version was stronger with the converging ribs. Still this rear became a warranty issue behind higher hp lowest gear ratio 4 speed cars, esp with slicks. Over the years have bought 4 pinion posi carriers from several '66 tripower cars that shelled their gray iron hsgs. All were hotrodded or raced. Have a nice set of 4.33's out of an early '66 car. Bought them from original owner of 4.33 tripower Goat. Only reason I can surmise they survived, is car owner pulled them & installed 3.90's shortly after buying the car.
All BOP GM divisions realized as they got more & more warranty claims, the fallacy of the normal gray iron 8.2 rearend hsg for performance use... basically there was a lack of pinion support. Thus each division's engineering redesigned or designed versions of rearends to handle the increased torque load. HP & Torque were on the rise, witness the 10 bolt r/e improvements that came in '67 & 68.
-At that time, Pontiac went to nodular 8.2 housings on what I'll call "at risk" 8.2 A & F-body r/e' s. These HD Safe-T-Track hsgs are rare today, & for restorers, nearly each year was different hsg casting number. HD Safe-Track 8.2 rearends also received hot forged axles, not the standard (light duty) axles.
These nodular 8.2's were, however, deemed not strong enough when Pontiac coupled near 500 ft of torque 455's to 4spd & auto's in '70. Through '72, lower horsepower & higher ratio (2.56-3.36) Pontiac 8.2 r/es received the standard gray-iron housing. Putting $1200-1300 in a gray iron 8.2 & thinking one has a strong 8.2 Pontiac r/e, well it is stronger than how it was originally, but there still is weak point.
-During '67 model year Oldsmobile ditched the bolt-in axle 8.2 rearends & went to the Type "O" rear. 12 bolt cover-10 bolt guts. For at least a year this r/e was avail with a special hsg, carrier, & 31 spline axles. Have one with 3.91's out of a 4spd '68 442. It's a resto piece. Same for the alum center section '70 442 type "O's. While the Type "O" is strong, it is not as strong as a propperly built 8.5 or 12 bolt. What aftermarket parts are avail for the Type "O" are expensive. A restoration piece or a white elephant, whichever you see it. On regular 28 spline iron Type "O"s housings I get in partscars, I usually disassemble & cut the outer tubes off so I can remove the lwr control arm/shock brackets. Occasionally need the brackets.
-Buick brought out its own '68-70 Buick 8.2 10bolt for '68. These were used through '70 models. This oddball 10 bolt used a carrier with 12 bolt bearing on driver side of the hsg & 8.2 bearing on the rh side. Basically BUICK beefed up the 8.2 housing & changed the dimensions on the pinion. 4 different ratios of carriers. Not that easy to find low ratio gears for (3.64's). Again. more of a restoration piece.
-8.5 A-body rears were 1st cast in Feb of '70. Buick & Olds used these A-body rears in '71 & '72 applications. Pontiac & Chevy got on board for '71 with a c-clip version for the F-bodys. There was even a c-clip & bolt-in axle B series version for '71. All original '71 8.5 posi's I've removed are the Warner-Motive cone style. So far been able to tell, the first "S" spring 8.5 clutch type posis showed up in '72 models. '73 Pontiac Service manual still gives info on the Warner-Motive 8.5 posi carrier, though have yet to pull one out of a '73.
Hope this was not to much rambling, just trying to get to the substance. Time has been at a premium, wish I could have taken time to present it better.
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