rewiring charging system

can I attach a extra 10 gauge wire with a 12 gauge Fusible link to the alternator and run it to the positive starter motor bolt. I figures this will take most the electrical load off the bulkhead wire going to the amp gauge. Will this work?
Yes but as Del said I would run it to the batt stud on the starter relay. and as a general rule you want to protect a wire/cable with a FL 2 sizes smaller than the wire and AWG goes in even numbers so a 12 ga FL on a 10 ga wire would be only (1) size drop. You might even go with an 8 ga jumper (& the 12ga FL). this bypass works but does render the ammeter somewhat inaccurate. I would suggest Nacho's bulkhead parallel bypass which is drilling out the 2 main in/out passages in the bulkhead & bypassing the brass terminals with (2) wires traight thru. #1 #1 #1 Clean all connections/terminals in the overall system including the ground path(s). Good luck! EDIT I'd actually go with an 8ga bypass wire then use the 12 ga FL