I believe the medium one will have plenty of power, especially if you have a good source of compressed air. I'd suggest around 100 PSI, minimum and enough volume to keep the pressure from dropping quickly as the reservoir gets drained. Be sure to leave a bit of clearance on the OD of the driver to avoid scarring up the cylinder head holes. 20 thousandths or so should be plenty. Have fun!
All the above can be done with a single driver shank, and a series of custom-fit tips that slip over the end of the basic driving tool. For instance:
www.ebay.com/itm/284394251543?Jerry
