since i bought my '83 GSL almost two years ago, i've managed to work out almost all the bugs. the following are left:

- vibration at freeway speeds. i think this may be one of the u-joints on my driveshaft failing. i heard that you have to replace the entire driveshaft in the '83. also would rebuilding the driveshaft be a feasible option? there's a guy in my neck of the woods who supposedly rebuilds and balances driveshafts and u-joints for $50 per u-joint.

- rear brakes rattle. i've got 'em all bled out fresh, but they rattle around when my foot is off the pedal. what would cause this?

 

vibration- check the cheap stuff like tire balance first
if not then yeah id guess the driveshaft

rear brakes rattle- take the wheel off and see what jiggles is what i would do

good luck
those last few bugs are the worst from what i hear, i havent even passed the first 5% of the bugs in my cars im sure hehe

gamble

 

thats good advice,,, pull the wheels,check the rotors,
calipers for play.even check the axels for play.you might try a junkyard driveshaft first. it's a 50/50 chance, but
it's a cheap way to test the driveshaft/ujoints