If you are looking for serious candle power...
You can go to any airport parts counter and ask for 12 volt aircraft landing lights which match the same diameter as your headlights.
These don't have the prongs on the back like a regular headlight. You have to run heavier wires anyway, and they screw to terminals on the back of the bulbs.
My dad has had a set in his '65 Impala for 30 years. I got the idea from him, and put a set in my first '69 chevelle.
Bad part about them is that you have to use a huge resistor to reduce the voltage to them down to 12 volts. Otherwise the 13.8 volts cuts their life expectancy. I didn't bother doing this, and both bulbs lasted until I crunched them into the I-74 Bridge that spans the Mississippi. Car lived... bulbs didn't.
9 years ago, these bulbs cost $65 each.
Alternatively, you can order KC-Daylighter sealed beam bulbs from J.C. Whitney which are extremely similar, but operate at 13.8 volts.
I have a pair ready to install as soon as I get finished with the engine.
Not legal for street use, but they'll burn the paint off the hood of the guy who is coming at you with is high beams on.
You can't "outrun your headlights" with those bad-boys.
The 160 watt H-4 bulbs I installed in my buick didn't come close to the intensity of either the aircraft landing lights, or the KC-Daylighters.
(the landing lights and the Daylighters are both narrow beams)
Run heavy wires, and use a relay off of the stock high beam wires.