if the vehicle has an oil press gage and the gage works while cranking the eng, then i would crank it till you see the gage move. if it has a warning light, and the light operates while cranking the motor, i would crank it till the light goes out. if the first two suggestions don't work for you then i would crank it over in two 15 second segments. an industry rule of thumb is to not crank an eng for more than 15 seconds, to prevent starter motor from overheating. so with the ign coil electrically disconnected, crank it for 15 seconds, off for 15 seconds, crank for 15 seconds. hook up the ign coil and start it.
now I'm making a few assumptions, that the car has been stored indoors, the oil is not some ultra thick racing oil 20w50 and the ambient temp is not super cold. and the people you have doing this have done this before, or at least have a clue.
now if your people want to take the time, removing the plugs and adding a slight amount of oil would be great but could be more trouble then its worth. chevy motors have their plugs under the exh manifold, buick v6 and olds v8 engines are easier due to the angle of the plugs. but if too much oil is added, it could foul the plugs.
if you change the oil prior to starting the eng, fill the oil filter as best as you can before spinning it on the eng. less delay in priming the eng.
if using starting fluid, a little goes a long way. if you get a pop back, don't confuse this with a back fire, a pop back is on the intake side and involves flames out of the carb. if this happens, keep cranking, it will pull the flames down into the motor where they belong.
good luck
joe
