What years were the HO 4.7's introduced? Was the only other option for the previous years just 4.7's?
Actually you could get the HO toward the end of 2001, that's how I ended up with one in mine. The previous owner got it changed out after multiple problems with the original, then I bought it the next year.
99 GC Limited - 4.7L HO V8, 6.5" IRO HC LA lift, F&R D44s locked & trussed, 242HD, IRO TC Skid, KMA Bumper, 35's 2006 Saturn Redline -2.0L Eaton supercharged I4, GMPP Stage 2, Custom Tune, AEM CAI, Ebiach Pro Kit w/ swaybars, EVO Ventus V12s (13.76 @ 103.85) 2006 Pontiac G6 GTP 2012 Nissan Juke - (hers) 2000 SV650 - naked, integrated tail light, sliders, corbin, pilot roads, RK chain & sprokets, D&D full exhaust, FactoryPro Stage I jet kit, +4 Ignition Advancer, Barnett race clutch 2006 Triumph America 900 - Full Dresser