From my preliminary research, ARH was available in 2002 on 3.0 and 4.4, but not with sport suspension (so no 4.6). In 2003 you could order along with models with sport suspension, except for the 4.6, which apparently did not come with it. Has anyone seen a 2003 4.4 Sport with ARH? From 2004, it was standard on 4.8 and optional on all others. Perhaps ARH came earlier than 2002, anyone?