Most of the relatively modern passenger cars (this includes T-birds) manufactured in the the U.S.A., that I have been involved with, have utilized the "hub centric" intention rather than "lug centric". This engineering provides an accurately located center hole intended to register the wheel "on center" as mounted to the axle which provides the hub register protrusion, with the responsibility of retention allocated to the lug studs & nuts. Hence the reason the wheel balancer locates off the center hole also. In wheel applications without this locating feature, each time the wheel is removed and reinstalled one will often have an off centered installation providing the felt vibration. We have encounter this repeatedly, and found the proper solution is to machine adapter rings, pressing/shrunk over the axle register and providing an O.D. appropriate to locate the wheel correctly. Note that proper rebalancing of the wheel may be required.
How is it, that the after-market wheel producers can decide (for a more universal application product) to reassign engineering responsibilities without anticipated failure? Unfortunately, this is a problem that persists. Also, keep in mind that another responsibility of the hub register is to support the wheel in impact loads perpendicular to the studs, to resist their shearing in their weaker plane.
These are not ten hole Budd rims on your old truck; note that even most newer trucks no longer use lug centric but have converted to hub centric for the notable benefits.