great thread for a sticky.. just keep as posts regarding the yorks and setup/conversion to on board air.
mine is a custom bracket we made, uses a 210 and v-belt clutch, the tentioner pulley is jsut a regular idler pulley that is pushed down in a slot. i use the overdrive kilby combo pulley and top rotolock/tube-o fittings from on board air. i also swapped my 105 amp alt to the large case 140 amp which requires a new rear bracket (oe part for trucks with the 140 amp oe alt) to be installed ($5 from gm dealership)
here are some pics..
custom bracket
setup unmounted
setup installed