Yet another will it fit question - 17 inch Bullitt wheels 67 Dart

In the front you'll need a spacer. With the 5.72" backspace rims the spacer only needs to be about 1/8", otherwise the rim hits the outer tie rod. The max backspace on a 17" OE bullit rim is about 5.6" in the front before the tie rod becomes an issue. You should be able to run a 245/45/17 no problem, and you should have no issues running a 255/45/17 either, although that's going to be the widest tire recommended for a 17x8" rim.

In the back, if you've got a 3" relocation and a minitub you can fit pretty much anything up to a 335. But the 17x8" will probably limit you to a 255/45/17. Not because of the space you've got, just because that's about all you'll find for tires for a 17" that will fit on a 17x8. The 5.72" backspace shouldn't be a problem with the spring relocation and mini-tub, you should have plenty of clearance everywhere. You'll probably have about an inch to the quarters, it won't look horrible but there will be some room. I'd see if I could find a 17x10 Bullit replica, there are a couple of tires still in a 285/40/17 but they'd need a 9.5" wide rim minimum. There is not much selection in street tires wider than that for a 17" though. A few drag radials, a couple of street tires, and a few autox/road race tires. Pretty slim for wide tires for a 17" that aren't drag radials or race only.