hanging unloaded doors?

Wrong! Doors first! They must be aligned to the quarters and rockers first. Then install the hood and align it with the cowl. Fenders come last. You would play hell adjusting the hinges on the doors with the fenders installed! All the gaps from the factory sucked anyway. Unless you are doing a custom job there is no point in fighting with the gaps. Get you a couple of large carpenters pencils and use them to get the gap for the quarter to door and door to rocker. That is real close to factory specs. Once these gaps are obtained then install the striker and adjust accordingly.

Ask me how I know or just look in my thread in my sig.

Correct. The forgiveness is found at the cowl end radius where fender, door, and cowl, all come together. The models that have a header panel in front of the hood are the most fun. Getting all 4 lines around the hood very pretty will result in more difference in those 2 forgiveness areas left and right.