Good evening to all,
I own a '78 Regal in excellent condition except for the 3.8(rod knock) and tranny (2nd gear went by by). I have found an '81 century 3.8, auto, etc., all good. How can I find out if any/all major parts interchange. The century has all the toys like power windows, tilt, etc. Body is shot.

Please tell me where to check.
Thanks,
Handydude