I am thinking about using a atv quad shaft drivin differential on a project im building to make it 4link. Which way does the drive shaft turn to make the axle go forward?  

it depends on wether you have a just one pinion or a secondary pinion.
rare but some do have a secondary pinion gear.
and which side of the pinion gear the ring gear runs on.

on a honda 250cc or larger shaft drive there is one pinion gear and the ring gear runs to the left side of the pinion, which means counter clockwise.