Welcome to the site! I'm not into the "bagged" thing, (nothing against it though) some really neat engineering/fabrication in some of those...The one dvcustoms on here is doing is WILD. The basics of suspension design though is the same. What were "some mods" you did to the axle...what did you change? Unless there is some "unique" 4 link suspension on there, a triangulated one will change length (wheelbase) & pinion angle some with ride height. Are you saying at normal ride height the rear axle has moved 3" from where it was prior to your latest mods or is this during up & down motion? Are you sure it was centered before? Glad to help if I can, post some pictures! Lorne