I have a '81 manual tranny, rear drum brakes, and without limited slip. I can get an '85 GSL rearend if I act quickly. I want to keep my propellor shaft ( the servicable type ). It has been rebuilt and balanced with new u-joints about 50k ago. The donor shaft has 188,000 miles on it and is not user servicable.

Please help me. I am about to have to make a decision on this. My questions:

1) On the swap, will my 1981 propellor / drive shaft fit and attach to the '85 GSL
differential ?
2) In making the swap to disc brakes, will my existing 1981 type brake master
cylinder work / do the job ? It has about 3500 miles on it.
3) What about the proportion valve ? Do I already have one that will work ? If
so, can it be adjusted for the new disc brakes ? If not, can I use an aftermarket
proportion valve ?

ThankyouThankyouThankyou !

 

The drive shaft will not work as is, You will have to change the penion flange from your current rear to the GSL rear.

 

Thanks, Hades12. That seems simple enough. At least no parts to buy

Surely there are others out there that can steer me in the right direction on the master cylinder and proportion valve questions. I would appreciate it.

 

You can use your current master cyl. I'd use a gsl pproportion valve or an aftermarket one

 

the master cylinder and prop valve are subject to debate. Some say to switch the master cyl, others say no. The part numbers are different so it *should* be changed, but many have said they left it as is with no problems. I changed mine to the proper gsl master cylinder. As for teh proportioning valve I don't think anyone changes those. Mine is the same the car came with.
like hades said the driveshaft won't work, but it *should* just be a matter of changing the pinion flange on the rear end. Never done that myself so I'm not sure if its as simple as it sounds, but I can't see why it wouldn't. HTH

 

Thanks, y'all. Is anybody out there certain about any of this ? ...like from firsthand experience ?