What ya gotta do is----heat the wishbone about 6" to 8" back from the pin that connects it to the axle, and bend it so that the major portion of the wishbone, beyond the bend runs parallel to the frame rail.----it should then clear the tire This means that the wishbone will now be too short to attach to whatever hanger bracket you have attached to the frame, so you will now be faced with either extending the wishbone, or torching off the bracket and moving it foreward.
---Don't do anything untill some of the other guru's weigh in on this topic. I think I'm right, but its been a long time since I used split bones. I generally build my own 4-link setup.