If you want to learn more about the tech involved in all of this, a great primer is here:

http://www.madelectrical.com/electrical-tech.shtml

There is an article on that menu page that discusses the bad idea of the vintage full flow amp gauges. They don't make amp gauges like they did in the 50s and 60s anymore. Good luck and I think you have the right idea!

Deve

1950 Chevy 3100 Deluxe Cab
1950 Chevy 3100 Standard Cab
In the Stovebolt Gallery
The Think Tank
More info and tips at Deve's Technet