I didn't want to drill through the bumper, either. Mine attach to a piece of 2" angle iron that bolted easily to the frame behind the bumper. I made spacers out of either 3/8" or 1/2" iron pipe covered in black heater hose and long bolts to bring the lights to the height that I wanted. The angle iron also gave me the ability to add a front license plate without drilling the bumper or the cowl.
I can send you some close-ups if you are interested.
Matt
