Is the belt line on the door aligned with the belt line on the cab?
A good tip that I have learned for adjusting doors is to completely remove the striker. It just gets in the way. Once the door is adjusted to the opening with the belt line aligned, the striker will usually be east to install and adjust.
Carl


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission