Front Hub Diameter for 65 Barracuda - Are there differences between 6 and 8 cylinder?

All the 4" bolt pattern wheels I've ever seen had the same center hole diameter, whether they had 9", 10" or disc brakes. I have seen people try to install the early 13" wheels onto a 10" brake car and have them wedge tight, but, it wasn't the center hole that did the wedging.....it was the inner part of the rim jammed onto the outer edge of the drum. The factory wheel you show looks to be the '65 and later wheel, though, so, that wouldn't be the issue here. Maybe someone tried some weird hub and drum swap from another vehicle? How about a photo of the drum with the wheel off?