If someone has not suggested it, may I suggest a thermal activated relay with a manual over ride.
Saves the pump at the beginning and can be forced on if necessary.
You will must likely need to improve your amperage output of the alternator as FWB has mentioned. A simple move to the Police alternator may be enough. I think that would be going from 65 Amps to 105 Amps.
You may want to improve the carrier wire from the alternator to the battery from #10 to #8 or a little larger.
Just my $0.02 worth.
