Any of the factory bracing listed in this thread: viewtopic.php?f=14&t=8126
F41 swaybars and steering box. Also the Fbody quick ratio box and front swaybar can swap.
Mid-'80s Fbody limited slip carrier.
Aluminum rear drums.
If you have plans to upgrade to a 200-4R in the future you'll need the proper crossmember.
Rally-pac gauges are always a nice find.
Factory buckets and consoles.
An 8.5 rearend is a rare find but you might get lucky.
Jeep steering shaft: viewtopic.php?f=31&t=32906&hilit=jeep+shaft
Blazer front brake upgrade parts: viewtopic.php?f=14&t=35747
Things that might be worth grabbing for resale here:
Anything manual transmission related.
Any T-top or factory sunroof (Astro-roof) trim and good rubber.
Aluminum body parts like Cutlass hoods and core supports and bumper supports. I think early Monte Carlos could have aluminum trunks.
We're pretty spoiled here in the NW. These cars are still fairly common in the yards and typically rust free. I'm sure you would have no problem selling nice body parts if you want to deal with shipping.