Install the drivers side shaft with the oil holes down & the notch on the end of the shaft should be facing the frt of the engine. Install the passenger side shaft with the oil holes down & the notch facing the firewall.
and to add:
torque the bolts to 17ftlbs - or snug with a 3/8" drive ratchet. make sure the lefts and rights are assembled so the rocker tip is over the valve tip.
pour a little oil over the rocker shafts, cover up and turn the key.