15x7 cragars on the front of a 69 dart?

I need some help.........does anyone know the maximum width of a 15'' wheel you can use on the front of a 69 dart with a 73+ disc conversion...........I'd really like 7'' wide if I can get them in there, Cragar makes them in a 15x7 with a 4 3/8 backspace................I've measured and it looks like it should fit.....but close, anyone have some feedback? they are custom order so they can't be returned

any help is greatly appreciated