Stock 70 Skylark 2.73 8.2 rear - what options for gear upgrades do I have?

best option

http://www.v8buick.com/showthread.p...t-10-bolt-posi-rears-3-23-amp-3-42&highlight=

 

You could compare the cost of new gears & posi for your existing rear,and the cost of the 8.5" 10-bolt along with the driveshaft getting shortened.
If you would have the new gears & posi installed by a shop,then find out what that cost is too.

 

Please - first ID the rear you have before going anyfurther so you know what parts to even start pricing out. Jim

J D

 

I don't understand the 70-71-72 bodies are the same all parts are interchangeable all of us have put one of the 3 years rears in one of the cars,there's no problems encountered doing it,3/4 inch you will never see it.Just my opinion.Bruno.

 

You do need to shorten the shaft when swapping from a Buick 8.2 to an 8.5. The reason is that the pinion snout on the 8.5 is longer,so it takes less shaft to reach it. I doubt you could get the factory shaft back in,but if you did,it would be in a bind. As you drive your car,the suspension moves up and down,and the yoke moves in and out of the transmission. If the driveshaft is bottomed-out,and can't move freely in & out,it won't end well.

If you do indeed have the 8.2,get a total cost for all of the parts needed to rebuild it - gears,posi,bearings/seals,and labor,unless you are doing it yourself.
Then you can compare that cost to the price of a complete rebuilt 8.5" posi rear,and the cost of shortening the driveshaft to accommodate it.

 

That's the Buick 8.2.

 

Yea,those 2-piece shafts were not intended for much more than going down the road.

 

What is the ratio? Confirm it is a Buick 8.25 rear 68-70 original
1.875 pinion shaft
Large driverside carrier bearing.
Please send a picture of the backside of the drum backing plate where the axle tube bolts to the backing plate. Thank you. Jim
Reason what to see if you have a GS or standard 8.25 rear.

 

Looks just like the 70 Buick rear in front of me. The casting number should be 1385724-F,located on the frontside of the pumpkin.

 

Adam, Jim monzaz was able to sell me a conversion bearing and I was able to put the 8.5 posi unit in my 8.2 housing. Mine is a 66 so that may be a difference. Just FYI.

 

It's a common bearing. The larger SET36 for the left side,is used on all 12-bolt Chevy rears,as well as other applications. The bearing for the right side is LM102949 and the race is LM102911. This bearing/race combo is used on all of the new 8.5" posi units,as they have a larger bearing hub.

 

Adam,

I have a 1971 8.5 3.08 posi rearend out of a Skylark and the driveshaft also. I've had it for probably 20 years sitting in my back garage. I watched the guy pull it out of the car but didn't see it in motion but was told it is in good condition. If you are interested, I'll make you a good deal on it.

Larry