This will be my last post as you are convinced it is a fuel issue. You need to do the two simple voltage tests. Why is that? Simple you stated you have 10.5 volts at the coil without cranking. So lets say your battery is fully charged and at 12.6 volts. 12.6 minus the 10.5 gives you a voltage drop of 2.1 volts. Now if you crank it and the voltage drops to lets say 9.5 volts. With your already 2.1 loss with out cranking should equate to this 9.5 minus the 2.1 equals 7.4 volts at the coil. Pertronix systems need more than 7.4 volts. These numbers may or may not be relevant unless you do the tests.