Hood fit on these cars is maybe the most important body panel alignment issue.

I do not use Afcos, so I am not sure how the tabs are configured. However, I would go ahead and drill the shell were the indentions are for mounting, and mock it up on the tabs using spacers to take up the excess play. Adjust the radiator support rods until the shell is parallel to the cowl vertically.

The next phase is setting the hood top(s) on and start getting the right hood line - running down hill from the cowl. Once you determine a height for the shell that leaves a nice hood line. you can move on to hanging the hood sides. You may have to reposition the lower mounts on the front crossmember to move the bottome of the shell out in order to fit the hood sides.

The most important thing is to mock up everything with just a few fasteners, clamps, etc. try to get everything looking good before you drill the final holes, mount the hood hinge assembly(if a 3 piece), lower latches(4 piece), etc.

Once you think it looks good, roll it outside and walk away 100' or so, then spin around and look at it - amazing how "shop blind" you can get looking at things from 8-10' away all the time.

Good luck.