I am looking for the rotors for the front of a 1999 Astro AWD for a friend of mine. I am finding sites that list AWD, 4X4 and 2WD and sites that list AWD/4x4 and 2wd. Was there actually a 4x4 model and a AWD or is it the same thing? Are rotors listed for a 1999 4x4 Astro ok for the 1999 AWD Astro? T...