Be careful on the temperature rating of the bulb: 3,000K is like a yellow, incandescent bulb you grew up with, in the 1970's; 4,000K is called, "Daylight", with a slight bluish tint to it; 5,000K-6,000K, is much more blue in color, and looks off, to me.
For Lumens, here is an excerpt from Wikipedia: "the
H7 (55 W @ 12.0 V,
1500 lm ±10% @ 13.2 V),
H8 (35 W @ 12.0 V,
800 lm ±15% @ 13.2 V),
H9 (65 W @ 12.0 V,
2100 lm ±10% @ 13.2 V), and
H11 (55 W @ 12.0 V,
1350 lm ±10% @ 13.2 V)";

"the
H4 (60/55 W @ 12 V,
1650/1000 lm"

. These are the standard Lumen (lm) outputs. When you shop for an LED bulb, check its color temperature (4,000K to 5,000K is good), and its light output (Lumens/lm should be greater than 1,650/1,000 lm, which is standard for the installed H4 bulb...).
Avoid fans on the bulbs! Fans will clog up with dirt on the road, and fail, causing the LED bulb to overheat, and burn out prematurely... Get one with silver braided loops of copper wire on the back: they're a heat sink, dissipating excessive heat from the LED, without moving parts which can clog up, and fail.
I would recommend installing a set of driving LED lamps on the crash bars for improved conspicuity, first, and foremost! They will create a triangle of lights, as seen on train locomotives. They did a study, and the triangle of lights allows people to accurately gauge your approach speed. They come in various colors (again, 4,000K-5,000K is good), as well as Lumens (the higher the Lumens, the higher the Wattage; don't overload the alternator!), but something to light up the roadway, at night, would be in the 1,000 lm range, per light. Their reach may not be far, so shop carefully for LED's that will reach out far enough, as well as having enough brightness. Cheers!
