Rewiring the starter cable wire and do not know amp draw of starter. What gauge wire to use for the positive and negative also wire from battery to solenoid and solenoid to starter switch.
a jumper kit (6ga) for boosting cars may be cheaper and long enough if you need the 16 feet .. you can always add protection with heat shrink tubing over the wire pair.
Caution with the jumper cables, those and most are aluminum wire, not good for marine environment and can’t be soldered to terminal connectors. Suggest staying with copper.
I had the copper coated aluminum cables on my 79 Cadillac & the negative cable fried the air conditioning dash controls, VERY high resistance All GM’s more than likely to save weight for better gov fuel rating. (Junk!). Replaced with xhhw type wire & soldered my own terminals on. My 62 Chevy P.U. has the same for easy 30 years. Can be bought at electrical supply houses in any size. I chose xhhw for the best insulation. Mine was “rabbit” wire. Came from wire pulls that always ran away :)!
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