I am currently using a 91 LS as a donor to my 89 Raider. I've moved a lot of stuff:
Cruise control
Headlight washers
Rear door light
A/C
Oil cooler
Pass bouncy seat
Other stuff (this is a theme)
I'm debating the LSD rear axle but it doesn't have disc brakes so I think I'll hold out.
I've pillaged a number of engine parts...cooling fan, fan clutch, distributor mount (I'm sure there's a better name), less rusty bolts and a bunch of other stuff I don't recall. I'm hoping to swap out a bunch of body stuff today: both bumpers, both fenders, both doors (original mirrors but am swapping out the power windows for crank) and some other stuff I also can't remember.
All that said, when I put the engine back together yesterday it had more leaks/problems than before it took up residence in the garage...in October. :-( So, I've not tested anything that involves driving. I'll likely have questions and pleas for help in other threads, myself. <sigh>