Blowing Maxi Fuse immediately...?
This drawing shows wiring close to what was done in '62 -'63.
That was OK with a slant 6 but runs the battery circuit clsoe to the exhaust.
Wire it like a later vehicle and the battery feed and otehr wires can all be bundled into the inner fender.
The fusible link can be replaced with a maxi fuse.
Fuses, circuit breakers, and fusible links need to be sized based on the wires that need to be protected.
The wire to the starter solenoid is only hot when the relay is on, so it doesn't need a fuse.
The heavy wire to the starter carries too much current to protect.
The main wires all connect to the battery positive. So if the fuse is blowing, then something downstream is connecting to ground.