So I purchased two 3rd members with new 4.88's and Lockrights in them for my 82' 4x4. After installing the rear, I found out that the bolt pattern on my stock driveshafts flange is smaller than the flange on my new 3rd member. I thought I might be able to just swap the flanges, but wouldnt that require me to have the gears "set up" again? What year 4x4 came with the bigger flanges?

Thanks for your time.

 

You do not have to set up your gears again. Try these, well worth the money and you will have both bolt patterns if you ever want to change gears again.
Toyota, Suzuki Samurai, and Jeep Off Road Parts

If your drive shafts have the small ends, you will need to change the diff side of the drive shaft flange to the 84 and up. They take the same u-joint as the older ones.

You can also re-drill your diff flanges for the older drive shaft which will be the cheapest thing to do. I believe they take a smaller bolt than the newer ones if I remember correctly.

 

Pre 84 is more of a rectangular pattern with 8mm bolts and post 84 is nearly square with 10mm bolts. Personally I'd drill the flanges for now and if you do any driveline work in the future swap the pair of drivelines out for the later stuff. The early stuff has a pretty limited range of angle while the later parts are good to about 43*.

 

Thank you guys for your help.

How is that 3rd member setup? I honestly have never taken one apart. Are there shims on the inside of the pinion shaft?