Two many power wires going to fuse box! Is there a better way?

If you want to add extra accessories on these old cars like gauges, fans, electric fuel pumps, etc. You really should add an auxiliary fuse block, the factory wiring isn't designed to handle all the extra current from all the extra accessories that we like to use.

Just run a 10-12 gauge wire from the battery, starter or starter relay through a 30 amp fuse to an auxiliary fuse block and run your accessories off of it, the 30 amp fuse will protect against any issues with the extra circuit while the individual accessory will have it's own fuse.

If you want the power to go on with the key, then just install a 25-30 amp relay between the 30 amp fuse and the fuse block and then run a switch wire to the ign side of the factory fuse block and it will go on when you turn the key on with out being powered with the factory wiring.