Alternator Sizing - Amp requirements

mopowers said
The fuel pump is just a Mallory 140. I just called Holley, and they said it draws 5 amp max, while the ignition I'll be running draws .7 per 1,000 rpm - so lets say 7 amps there. Looks like a line lock draws about 2 amps. After some searching, looks like the fan I've got pulls about 35 amps on high speed, which is about 50 amps total so far.

I'm just unsure what the load is of high beams/brake lights.

Thank you! The car will have all new wires, as I'll be wiring it from scratch eventually. There will be no bulkhead connector, or ammeter.

This is great information. Thank you! Do you run an electric fuel pump as well? Which alternator did you go with?

I have a Magnafuel QuickStar 275 electric pump. I have not measured current but it is a bunch...I think its around 6-8 amps. As for the lights, I used LEDs for the marker lights and backup lights to minimize current. You can add up the lighting currents for the bulbs you pick but even at 12v, there's plenty of margin. I'm using a #75191 Powermaster 95A single wire alternator - there may be other/ better ones but I'm happy so far with this one. Put it this way...if I had it to do again, 95A would still be my choice for size. Hope this helps!