alll my 740's and 240's have 14" wheels. I seem to be able to swap them ok.

on the weekend I went to a used tire shop with my ford van, same issue, he encouraged me over and over to try to find some larger wheels. I guess bronco took that size too. He said the 14"s are getting harder to find and new ones getting more expensive. I'm not sure what to look for.

I guess you can likely use a lower profile tire but increasing the wheel size would lower your power so unless you do a lot of flat highway driving and feel you benefit from higher gearing, it's probably not a great option. you give up on one end and lose on the other end. Its not like you get something for free. you might find different ratios you can play with if you want o change gearing you might compare stts of the wagons to the sedans and maybe see a difference there. but that's a lot of work or expense. if you go to a lower profile you get a rougher ride. For me that would just mean extra pee stops but some may like that.