Reference Picture - Duster/Demon

When I mount the doors on my cars, I always make them fit, and the body lines correct before I ever put the door striker posts on. Then I just make the striker align where it needs to be. Getting door and fender gaps right is like trying to dress a mad, fat baby! You just gotta keep your patience.....lol. Also, the gaps can look big while the car is in light gray primer. That awesome Charcoal color you chose will close them up a bunch to the eye when it's painted. Be sure not to get the door to fender gaps too close, and put the ever so slight outward bow in the fender by pushing it up from the bottom before tightening the lower fender bolt on the rocker panel. You don't want that teensie bow to be noticeable, but rather just enough to allow the door leading edge to go behind the fender when it gets XX mils of base/clear on it. Good luck to you. The part you're doing is a pain in the wazoo....but you'll get it!