The early GMT800 2wd trucks had front coils, at least my 99 Silverado does. I thought that was true for all 2wd 1500 trucks of this generation (except some Silverado SS). Isn't that also true of the early GMT800 SUVs? I thought at some point the SUVs switched to front torsion for all models. The L59 donor engine I swapped into the 99 was from an 04 Yukon XL and that one had front torsion bar in a 2wd configuration. I pulled the engine and thinking how the torsion bars kinda limit access to things like motor mounts, etc. But I'm not sure of the late 1500 GMT800 trucks.
And, of course, all the 2500HDs+ (and 1500 HDs) had front torsion bars, 2wd and 4x4. Same as the Suburban 2500s, maybe the Avalanche 2500s too? I'm not familiar with Avalanches. The 2500 Non-HDs 2wd also front coils.
I've never really figured out why some had front coils and some had torsion bars. My only guess is it had to do with GVWR or maybe to keep everything simpler from a manufacturing perspective?