6 volt vs 12 volt

I have a 50 Town and Country that has the straight eight engine. I am running the original six volt set up and have never had a problem even in over 100 temperatures in the desert. I have driven on many trips in this car over 500 miles and have never had a start up problem. I also replaced the cables and checked all of the ground points and am using a standard six volt battery. All accessories work perfect all the time and I have never had a problem starting even when driving with lights on for long distances. I have also never experienced any over heating problems with this car in the fifteen years that I have owned it. It has never been rebuilt and has 36,000 miles original. I am also running the standard fuel pump for the car. It has been a great trouble free car and can sit for long periods of time and still start with no problems within a few turns of the motor.