I have seen one guy do that as you described. Jerre Heyer did it on his F350, but when he came to Taconic BBQ last fall, he had the strobes running and it was burning/melting the len of clearance light! It is because the strobes generate alot of heat, and with the strobe in a such tiny space, they have no way of cooling off unless you drill a vent hole in the clearance lens (ouch). They may look cool, but I would suggest you to look into magnetic mounted roof beacon or strobe. Much more simple that way, cost would be less, and significant increased visibility (360 degrees).