What size tires will fit on stock dart 15" wheels?

Honestly the 225/60/15 should work with the SBP front. I ran 225/60/15's on my '74 Duster on 15x7's with 4.25" of backspace, all I needed to do was adjust the front fender corner to bumper braces to their maximum. But with the SBP brakes you should have more room than I did with the '74 BBP disks, by a good 5/16" or so since that's about what's added to the track width with the later brakes.

Looking at that list I don't see a 225/60/15. The 215/65/15 would be closest, but keep in mind that although that tire is narrower, it's also taller. Again, it should work with that backspace, but every car is a little different. You shouldn't have to cut anything, but some adjustment might be necessary.