Breakers go by amps only. I only had 5 breakers when I received my truck. I had no luck finding them back then, so I used good old ATO fuses . It actually works out good. As I went through systems one by one, I figure a fuse would blow immediately, where as a 'unknown' CB could be defective and either not trip, or not set. I never had any of the fuses blow, and they are still there today. Why change what works?