[Vic Piano]

If your existing 6 volt wiring harness is in good condition, it will work fine with 12 volts. If you are going to replace the wiring harness, I go with a 6 volt (heaver gauge wire) harness anyway. Alternators and brackets are available through most “specialty after market” places like Speedway. I'd mount the fuse box somewhere that is easily accessible either inside the car or under the hood.