I have a 1941 H with a 6 volt positive ground system that does nothing but go to a few tractor rides and parades each year. It has always be sluggish to start. And very sluggish if its 30 degrees or less outside. I have known forever that I should put on thicker battery cables to improve the starting. Well today I finally did. I replaced the 2gauge cables with 00gauge cables.(I had to buy bulk cable and make them, which I suppose is why it has taken me 3 years to get around to actually doing it). Well, seeing is believing. That starter just snaps into action and the engine just whirls. I am posting this for anyone here who like me knows they should do it but have been procrastinating. The thicker cables will make it jump to attention when you hit the starter. It is definitely worth the time and money.