After working on my truck this evening I realized that I was just guessing at the body panel gaps.
When assembling a truck after a complete tear down what is the average gap between the body panels that I should be trying to get?
I don't have a specific answer for you Mr. thirsty, but when I hung my doors, I just tried to get an equal gap on all 3 sides. Top, bottom and rear.
If the doors are just shells, I leaned on the side of a bit high at the rear side, meaning the body line of the door was like 1/16 to a short 1/8" higher than the body line of the cab. That way once you get the window mechanism / glass and door hardware in, it would settle down a bit.
I would estimate my gaps at about 3/16 to 1/4".
When setting the fender to door gap, you can't get them too close or the front door edge will hit the fender when you open it.
I know this doesn't help you too much, but it's all I had to go on when I started hanging my panels too.