Like Dave said, been done mucho mucho. Yes, the steering box can be a problem with some fits, and the bell housing crossmember causes most four tube full length headers on stock frames to hang real low, and they will hang below the frame, so if you're lowered, you will probably be banging your headers on the street some. Shorty headers work much better than full length four tube collector types, because you can tuck the head pipe up tight to the crossmember, and work around the steering box with the single pipe.