1970 GMC C2500 rear axle hub diameter?

[tow rig]

Nearly all factory installed wheels are hub-centric. The 1970 GMC had steel wheels that mated tightly to the hub. I know that many aftermarket wheels are designed to be more universal, and center off of the lugs, in order to have a single wheel casting be useable with several applications. My opinion is that lug centering wheels may be less than ideal, especially for a HD truck that will be carrying heavy loads, driven in rough terrain, abused with dragstrip launches, and/or towing a trailer. Anyway, it looks like my question is turning into something that I haven't asked. Are hub-centric rings needed for aftermarket wheels?(This is a simple google search that I have already done. The jury seems to be about evenly divided on the subject.) Thank you for sharing your experience.