After the OE ECU is reprogrammed, you are ready to roll. The Yukon was run on the dyno to get some comparison numbers. After the supercharger install, the Yukon pumped out 272.9 hp at 5,350 rpm and 287 lb-ft of torque. This was an increase of 72 hp and 59 lb-ft of torque over stock -- not bad for a day's work.
2001 GMC Yukon Vortech Supercharger Installation - Part II