[SilverCompG]

From what I understand, you need to have a 2003 or newer for the nav unit to work. Gm redisgned the dash in 2003, thus the prior models don't have the same specs for the radio area. GM does make 2 Nav units, one for the Lux amp, which is the Denali and Escalade, and one for the Non-Lux amp, which is for the Tahoe, Silverado, Avalanche, Hummer, etc... Must have the bose speakers as an option for it to work. Each unit does have a different part #, and as far as I know, that is the only way you can tell them apart. There are a few older Nav units that are non-touchscreen, but from what I've seen, most of them are for the Lux amp.