Middle plug on the passenger side is line pressure. Should have pressure in all forward gears. Front plug is front servo and should only have pressure in third gear on both manual and auto valve bodies. Rear plug is for manual low and reverse. Standard line pressures are around 55 at idle and go up to approx. 85-90 lbs. with the kick down lever all the way back. Manual shift valve bodies usually have around 90 and up at idle for line. That should get you started on your tests.