Are Mags centered on the Lugs or the Center Hub?

[11echo]

I've got a 64 Chevy C10 ½ ton project, I'm changing over to disc brakes, already got donor spindles, calipers, & rotors off a 77 C10. My issue is this I found a pair of American Racing 200S Daisy mags, 15x8 with 5 on 5 lug pattern ...I want to use, but the center hub diameter is larger then on the rotors. So I'm thinking if the mag is centered with the lugs am fine, but if it’s centered on the center hub of the rotor then I'll need an adapter. ...Anybody know for sure? THX!