It may not apply to yours exactly because I did a complete custom front hanger/engine swap thing and had a 3 inch body lift, but here's mine. I moved the box forward about 4 inches also. Enough so that at full turn, both ways, the drag link and tie rod are nearly parallel. I was building the entire front end at the time so I plated the frame on both sides of the box mount with 3/8 plate and then made extentions to my front body mounts that allowed me to reistall a part of the original rubber insulator using some tubing. Being that my front bumper was going to be all tube, it would blend in well enough.
It worked out well enough that we just did the same thing to my brother in laws rig that we're building but he has a 2" body lift and it appears to be working fine. The only issue we had with both setups is that we had to order longer drag links from marlin either due to the box location or the fact that the 3/8 plate shifted the box over slightly. Running Hydro assist and 40's without firewall clearance issues. the body mount is kind of hard to see in the picture, but you probably get the point. I did it to both sides to be uniform. good luck