I give up. It doesn't depend on whose kit you use. There's only ~9/16" from the original front hanger to the frame, as crackedback mentioned. So, you can't move the front hanger 3/4" in unless you put the front hanger inside the frame rail. Since MP's kit doesn't do that, the front hanger only moves about a 1/2" in, certainly less than 9/16" because with the MP kit installed on my car I can tell you the front hanger isn't slammed against the frame rail, there's a small gap.
Put the perches wherever you like, it doesn't mean that's what you'll get for clearance. Maybe you'll get a little more clearance by side loading the spring, but you won't get it everywhere. Somewhere between the perch moving 3/4" and the front hanger only moving a 1/2" you'll get your actual clearance number. And really, it doesn't matter, because moving the perches in a 1/2" puts them in line, or slightly inside of the wheel tubs. So, you'll rub on the wheel tub before you hit the spring anyway.
