If engine is destroyed beyond repair, then would have to get another block. That would not be numbers matching. Swapped out rear end not numbers matching. If you replace trunk gutters, then they are not numbers matching. After market doors work pretty well have them on my car. When putting on the quarter panel top where it meets the door had a small point and wish I had cut it off and welded it up. At the point of the build, it was do I or don't I cut that off. LOL.