You need the front spindles, which nowadays are the most expensive and hardest part to find since these trucks were only in production for three model years. Same 15" rotors, then you just need to choose which calipers to use, 04 sliders or 05-06 fixed. For early 3rd gens it has to be 2wd only, the 4wd spindles are too different. Not sure about later 3rd gens. According to the guy I sold my original 03 2wd spindles to, the 4th gen 2wd's use the same spindle as the 2wd 3rd gens; logically then the SRT spindles should bolt into a 4th gen 2wd.