Used Weld Prostar

I have a chance to pick up some Weld Prostars. The guy said they are 5 lug 15x8 and they came off a 1972 Maverick. I'm not sure of the back spacing but is the lug pattern the same as a 5 lug Foxbody? What back spacing would they need in a Foxbody application? These would be for the rear obviously. There are 4 of them and he said they were all 15x8. If I got all 4 I might be looking to sell two or maybe swap for some narrower ones for the front. My car is still 4 lug but just thinking about future projects.

Originally I have seen the wheels sitting out by the shed from a distance. I met with the guy and looked closer today. It turns out they are Chinese knockoffs of the Weld Prostar. Solid aluminum and a 4.5" backspace. I thanked the dude for his time and moved on.