Such a modification is probably illegal.
Not that you will be bothered by the law, All those retrofit HID kits installed into halogen reflectors are illegal, but it does not stop the masses from blinding the rest of the masses with high glare poorly aimed blue floodlights? Not often, but I have seen a few offenders being written up.
If the goal is brighter more effective headlamps, making sure the headlights actually receive battery charging voltages makes a huge difference. The difference in lumen output between 12.0v and 14.5 is huge, 50% brighter at 14.5v.
I was suffering nearly 3 volts drop over my stock wiring. I used the stock wiring to trigger relays and made a new 12awg harness. My voltage drop is now 0.3v and very few vehicles that pull up next to me at night, have better lighting, and I just have sealed beam 6054 headlamps, which are now where near as capable as modern housings.
The following site should be perused and studied by anybody interested better forward vision at night.
http://www.danielsternlighting.com/