To align clutch spline, engage fourth gear, a couple of bolts in the drive flange holes on transfer box and rotate output shaft to front while you hold the rear output flange or jam it to stop rotation. Once the spline slips in and is entered put a bolt in each side LH and RH of bell housing at horizontal centre line, start to tighten evenly each side, making slight movement of the rear of the gearbox up and down until the nose end of the first motion shaft enters the spigot bearing. At all times trying to keep the gap engine to bell housing equal top to bottom and side to side.