Is there any issue with me using an exsisting 8.2 diff. with the addition of 3.08 or 3:23 pinion and posi unit in a car that will have a mildly built 455 with a TH400 tranny? Can it handle the torque?
Well, the 8.2 is what they put in the 1970 455 cars, but the 8.5 replaced it in 71, probably with good reason. I would imagine it just depends on how much you abuse that 8.2 ... I'm sure someone here has real world experiences to relate.
Handle it There used to be a guy named Chuck Schoolmaster in the northwest who had a 70 Olds Cutlass called Joys Paycheck that ran mid 11s. He ran a 10 bolt for years. He could pull both front wheels off the ground. I'm not sure if it was an 8.2 or an 8.5. But it doesn't sound to me like you are going to be putting out as much power as his car was. Unless you get crazy I see no reason why your 8.2 wouldn't do just fine. Maybe if you were running a 4 speed there could be more of a chance you could break it. I say go for it. :TU: Good luck Bob Harris
I have the original 3.42 8.2 10 bolt in my GS. So far I've run 12.75@104.5 with Mickey Thompson ET Street Drag Radials. That was at a slower track. I expect much better times at Cecil County this October 13 and 14th. I hope it holds, because I'm going to find out at Friday's Test and Tune.
First QUESTION... What year & type of 8.2 rear??? Don't see anything indicating you have a '68-70 BUICK 8.2 rear. Got Posi? :3gears: Roger
Its a 1968 buick skylark automatic with a 8.2 and 2.73 gears, I believe. I won't be running 11's or most likely low 12's either, but my plan is to run better than 13.4. The set up I'm looking to use is: 455 with the heads converted to stage 1 heads. Edelbrock rpm intake with an edelbrock or holley 800 carb. TA 290-94h cam forged pistons TH400 I would like a car to run a minimum of 13.4 1/4 mile ET Also, the cam was suggested by a reliable source from this board. In your opinions, do you all agree that it will accomplish my minimum ET and street ability with power brakes?
Reason I asked which 8.2 is there are varying strengths of 8.2 rearends. The gray iron single rib early 8.2's are very weak. Buick used the single rib 8.2 in most '64-67's, & tons of early Olds A-bodys used them as well. One can easily throw $1200 in new parts at one of the gray iron single ribs, & one still has a very weak rear due to the lack of pinion support. Comparing all of the different versions of 8.2 ten bolts, the HD nodular Pontiac 8.2 rears & the '68-70 Buick 8.2's are the strongest of all 8.2 rears. While both in #1 shape will hold up to the rigors of a 12 sec auto A-body, both are expensive to build, esp when one only has a higher ratio single track rear. This is esp the case with the '68-70 BUICK 8.2's , as nice quality used low ratio gear sets & posi carriers are very very hard to find. Not building a cutting edge Concours show car that has to have its original rear, the 8.5 A-body rear is your best bet as a rear swap. Personally have built over 400 of these. With an automatic & in the 13's or 12's, a blueprinted 8.5 A-body rear will handle the torque & allow future upgrading if one plans going a lot quicker. Got Posi? :3gears: Roger
12 bolt 8.2 8.5 OK Right off the bat...It sounds like your putting a 30 year plus rearend expecting it to hold to a newer engine trans etc. combo. Any size rear - that old will have issues quicker than any rebuild gone through rear. So that alone is a hurdle and something to think about . If a rear is build for a purpose backlash upgraded parts like new designed posi newer quality bearings and races etc. The 8.2 will do fine esspecially if your a street car . Slicks trans brakes with high stall or dumping clutches at high rpms are tough on the complete drive line componets. At least it has bolt in axles so hopefully the damage will be minimal if there is a problem. Jim
