i'm curious as to what you're trying to achieve by doing this. a h3 bulb has a transverse filament, while the 9006 bulb has an axial filament. if you stick a h3 bulb into a lamp housing designed for a 9006, you'll get a crappy results because:

1) the h3 bulb is so much shorter so the filament wouldn't be in the right place to generate the correct beam-pattern originally designed for the 9006.

2) due to the transverse filament, you'll get a big block of light that will shoot all over the place and no amount of adjusting would fix it, and you'll have everyone high-beaming you back because you're getting light into their eyes.

as for the h4, if you're able to place the low beam filament exactly where the 9006's filament is, then what you'll get is the same exact beam pattern, except 1/2 of it is cut-off because of the little shield inside the bulb.

my advice: this project/idea is not worth trying.