I stripped my 87 240 sedan down to the shell and may be getting an 82 wagon. I was wondering if any of the body parts would interchange and if the interior would work in the 82 since the 87 interior is almost perfect. Obviously, the headliner and rear seats would be different, but stuff like carpets, door panels, etc. is what I am curious about. Also the 82 has an 84 engine in it and I have all the stuff from the 87 B230f engine and the five speed tranny. I know the older 240's had the M46 trans and the 87 is a M47(overdrive included in tranny), is there a difference in length and can I just use the driveshaft from the 87 in the 82(82 is an automatic now)? Will the hood, doors, bumper, fenders interchange? Thanks for any info.

Any 87 sedan interior parts will work in any 82 sedan. Then as you note the wagon differences apply, but one more thing, the newer seats have a different headrest that will not swap.
You could swap the M47 with driveshaft and flywheel and clutch but you would not have speedometer function.
Will the hood (no), doors and panels (yes), bumper (different bumper and bumper shock but they might swap as a unit), fenders (no) interchange? However if you swap the fenders and hood and lights as a unit, it whould work.

in oreder to swap the front end body panels you do have to do it as a unit. This would also include the face piece that the radiator and lights mount to though. They redesigned these to accomadate the larger headlights. Another thing you need to look at is are the wiring harness's for the headlights able to be swapped. I cant remember if you can plug the newer harness's into the old ones or not.