Fogs have to be mounted a minimum of 12 inches from the road surface, and no forward facing lights can be higher than the lowest part of the windshield.
Fogs must also be relayed to low beams in many states (I know for a fact PA checks this, big fine for no proof).
Regarding mounting, it's a tough quesiton. As a rule, fogs are the lowest mounted light and have a very sharp horizontal cut that is basically level. So if you measure level from the light mounting point, that's where the beam will go. I suspect a few lowriders won't be pleased, the question is will the cops. They do have the discretion to issue a nuisance ticket. BTST.
Hella 4000 fogs are a bit of an overkill on an 80 especially that high up. I'd consder a lense change and put driving or pencil beams in there. Otherwise what you will probably end up with is turning the fogs down, which will wash out the first 20 feet of road with a hot spot, kinda negating the whole idea of a 'fog' to begin with.
Not sure the reasons for the fogs, if it's fog, then you want to get the lights lower down.
my .02
Scott Justusson