Here on the coast, there are specialty electrical shops that service the marine industry. I found out they can make custom battery cables with copper terminal connectors that are a lot tougher than the lead ones that come with off the shelf types. I had a set made up for my '50 gmc, and believe the investment was worth it. With 12 volts, the bigger cables may not have been that much of an improvement compared to 6 volts, but they still help. Another big help is to run the ground up to the starter and attach it to one of the two bolts there. I then run a separate ground to the frame as well. With the two cables right to the starter, it goes right to work when the button is mashed to the floor!
