1984 GSL Driveshaft question
 

Hey does anyone have any experience with this model year driveshaft? Specifically changing the U-joints out of them and where can you buy a replacement? Also, I have a 1985 GSL-SE LSD rear in the car now, will any 84, 85 driveshaft bolt up to the rear? I had a mechanic replace the old rear with this one and he said he had to replace the driveshaft because it wouldn't bolt up to the new driveshaft. Was that just BS? I know when I drive the car now I have constant vibration and the transmission clunks going into gear. I appreciate any information on this, thanks.

79-82 driveshafts are interchangeable and had replaceable u-joints. 83-85 driveshafts are interchangeable and do not have replaceable u-joints. the differential flange is different on fomr 79-82 and 83-85 and thus the rear flange on the driveshaft if different. 79-82 has a smakker flange on the differential.