I too don't think that information is correct. There is more of a chance at getting a ZL1 engine with a Rockcrusher M-22 in these cars than an archaic Gen II engine. It has to be a 6.X liter LSX variation; NO WAY could it be a Gen II... All the optispark and water pump problems, not to mention I believe it was either the hydrocarbons or nitro-something emissions were too high because of the LT-series compression ratios and combustion chamber designs. Gen III are far more advanced (let alone Gen IVs) so there is just no way, IMVHO.
05 Hummer H2 SUV on OEM Air Ride
Forged 11.1:1 408 LQ4 (K1 crank & rods; Mahle pistons)/CPP LS3 CNC heads/BTR Stage IV LS3 cam and valvetrain/home ported L92 intake manifold/ported 90mm TB/custom Volant CAI/mid-length headers/AFE dual 3" CB/Corvette Servo/el cheapo lift/Cognito UCAs/e'fan conversion/aluminum radiator/Moroso catchcan/HPTuners by me/LED exterior lighting/Pioneer AVH-5600BHS/Pioneer GM-9601/2-Pioneer TS-W310D4/Obcon Labyrinth dual-12 box/lots of other stuff