77 f 100 two questions

First question is were can I find a data plate decode list for this truck? I've been trying to decode my axle it is a 47j.Second question is I am going to lower the truck 4'' in the back and 3'' in the front and want to go with 10'' wheels on the back with a 4'' back space, is this too mutch rim for this truck and what size tires will work on this rim without rubbing?Thanks [img]/phpBB/images/smiles/icon_smile.gif[/img]