9004/9007 conversion, thick wires

[BenediktRochow at oaktech.com]

I'd like to try this out temporarily, and am wondering
whether I'd get only low beams or only high beams
if I do not change the wiring. In searching the archives,
I find statements going either way - "ground and high
are reversed" (causing no low beam) as well as
"ground and low are reversed" (causing no high beam).
Does anybody know for sure?

With regard to wiring harnesses for H4 lights, I've had
trouble finding a source for thick-gauge wires (other
than 14 and maybe 12 gauge wires in 110V extension
cords), but now found that my local Ace Hardware has
everything down to 10 gauge wire in its tiny auto section
(cheap-ish: 7 feet of 10 gauge wire for $4).

thanks,
-gbr