The extended cab is not right for a 47-54 AD truck, they take a regular cab long bed chassis so you might want to check the wheel base on the extended cab. On an AD the S10 4WD rear is STILL too narrow but might be just right for a 46. We use a 1.25 inch spacer on the S10 to put the rear wheels in near factory location with the standard back spacing. Have step by step build pictures of an AD going on an S10 but might not help on a 46 build. This swap has been done many times so a search should get lots of hits. Good luck.
