Repro door hinge plate issue
I have a dynacorn repro door for for 68 that I am trying to install. Upon trying to fit the hinges I realized that the plates in the door have too small of holes. I did some searching and read that people have had luck drilling and tapping the holes. I drilled and tapped the holes to 5/16"-18 which is the size the old bolt threaded into at Home Depot, however, the bolts still don't fit. What the heck did I do wrong?
1968 fastback 351w