One thing I've noticed during my adventures in hot rodding is a distinct lack of heavy power distribution blocks in the car. I need to completely rewire the hot rod to clean up all the relays I've added as well as all the hacking that has taken place over the last 45 years.

The alternator stud will be a good place to supply heavy amperage to the fan. Make sure you've got a heavy relay too. My Mercedes fans will spike at 50 amps and settle down to 40 while running. the typical Autozone 30 amp relay won't cut it. Luckily, these fans have a built in start up capacitor. I can run a heavy lead (fused of course) to the fan run lead and a tiny little switched lead to the start up wire.