This is a great topic and an interesting question. I am a newbie here but this question drew me in. I have been investigating this myself in detail as I want to place a set of the HD aluminum rims on my 02 Express 3500 that we use as a camper and college hauler. I currently have the steels with trim rings but want to upgrade rims when I get new tires in the not to distant future. I borrowed an HD rim from a friend to check fitment on the van. Bolt pattern was fine but there was no tire on it to check clearances. I took lots of measurements and came up with the following for what it is worth.
The aluminum wheels are 16x6.5Jx28 which is a 6.5 inch wide rim with a 28mm offset. The steels are 16x6.5 but there is no offset marking that I can find so I kept measuring and as near as I can tell, the offset is very close to 17mm. So the difference in offset (11mm) equals .433 inches (about 7/16") closer to the center of the vehicle. Both sides combined narrows the track (distance between the tires) by a little less than an inch. This may be considered very minor but I am not sure. I do not want to affect the vehicle handling or stability. I considered spacers to compensate but then thread engagement of the lug nuts may become a concern unless the studs are replaced with longer.
Would love to hear of someone with firsthand experience.
Thanks for listening.:happy: