4. The shroud has two long flat areas along the top and bottom that have three holes drilled in them. This is where you will mount the shroud to the outer supports of the radiator core. This shroud is designed for radiator cores that have the outer supports flush with the core itself. Our radiator’s supports are not flush with the core, so we needed a small little spacer. Yes, we are drilling into the radiator here with some self-tapping screws. The outer supports are hollow and do not carry any coolant, but confirm this on your radiator before drilling anything.