So i just got this 01 yukon like 2 months ago to save on gas from one ton dually big block kenne bell super charger 12 mpg on good day but it halls. So far ive done volant cool air, changed all fluids to syn., e3 spark plugs, msd wires, and other maintenance items. I installed dual head rest dvd from myron davis, just bought viper remote start with window module and stereo sys. pioneer deck n shallow 10s under sec seat, jl audio components, alpine digital pdx 5 channel amp and will get installed soon. have electric flex a lite fans in the shop 4 it and lookn to get throttle body spacer n exhaust next. dont want loud sound though any good quit exhaust on these trucks. also want to change ratio on a set of roller rockers. under drive pulleys would be nice but cant find any, got some info on those. so any insight on quit exhaust and pulleys would be great. once i get all mods done will get cutom tune also. cant post up pics yet but you wanna c other toys check out myspace have some on there. thanks guys n if you got any questions i can help with give me a shout. mark