I'd opt. for a minnie gear drive starter 3.5 HP's can be had for a little over $100.00, also as Josh and David said use a ford solnoid and good grounding.
Be careful if you go to 16 Volts, make sure your delay box is setup for 16 volts. Some biondo delay boxes are 12 volt only.
Also on starting get the engine spinning then flip on the ignition switch, if you have the distributor locked in.
JMO
Zip.