If it is the same size as the original then yes torque it down
I'm replacing all mounts. I lifted and replaced one side at a time. After all the new mounts were on I started to torque in two rounds. First to about 30ft/lbs and then to the final ~55 ft/mounts.
Did you snug them down all first before you started tightening them?
That's how you're supposed to do it and basically how I did it. One thing I did do before I snugged them all the way was get them finger tight and then go around and make sure the body was square (as close I could get with a truck like this) on the frame using various reference points. However, I had my body all the way off the frame and on a rotisserie, and replaced the body bushings when I put it back together so it might be a little different than replacing the body bushing and not removing the frame from under the truck. I wonder if you backed them all off and tried the process again, but starting with the one bushing that has the gap first if it would change anything? Are the doors, front fenders, and hood still on it? You could measure your gaps at few locations and see how it effects everything as well.
Doors don't fit that great. Its been in at least two collisions in its lifetime. Adding some shims just behind the B pillar mount may help with the door alignment. I'm going to loosen this one mount and see if it helps with the door alignment.
Those collisions will cause trouble for sure on fitment. This video is what I used to dial the body in, however I still have not worked on the door gaps or fender gaps yet. You will just have to get as close as you can and see if works for you. It takes time with old trucks, especially one with history like yours.
