Yes, the backspacing of the rim is always a concern. I did some trading for a set of 16" rims & tires off an 05 Mustang. They have, like most newer rims, a lot more backspacing! And, the newer hubs are narrower. I couldn't get the fronts on due to the small center hub hole. The rears went on, but something on the driver side made a knocking noise when making a turn! I know spacers would work, as seen on Zenish's van, but I didn't feel like messing with all that. I've seen many, many Aeros with the 16" Explorer alloys. And, I picked up a set of 15" s off a 99 Explorer a while back. I bought a pair of new Falkens, and put them on the rear of my 95 for 40K miles. I didn't want to buy new tires for the front, since the alignment was off and tire wear was uneven.
It takes a 1/4 inch spacer and longer studs in the front for the Mustang wheels to fit. A 245 40 r17 is the widest that will clear. On the rear axle if your bushings have any wear the tires will rub the the body. I found this out when I tried to put the wheels on my current van.
