85 gsl rear end?
 

will an 85 auto gsl the whole rear end suspension brakes diff everything be swaped into an 81s? i heard something about brake line thread or something like that is that the only thing? has anyone ever done this or a post that you know of cuz i cant find anything specific enough on any ass goodie swap from any gsl or se to lower model year?

the post your thinkin of is down a few. it's on an 80. the 79 & 80 have different threads than 81 & up. so it should fit in like a glove on an 81.

You *will* need either a '83-85 manual driveshaft, or swap the pinion flange from your current diff to the new rearend. The driveshaft bolts up differently starting in '83, and the automatic used in '84-85 used a manual-incompatible driveshaft.

oh yeah.. that too.