Lefty's installation is the same as reassembling a factory transfer case, but with a few variations that come with the relocated front output. The back end of the 2WD/4WD shift rail and shift fork will have to be tapered for proper clearance inside the case. How much material needs to be removed? As much as needed to allow the shifter a full, complete throw without binding against the inside of the case housing. Jay stuffed shop rags over the internal moving parts and ground away on the shift rail and shift fork.