OK, we've seen this done wrong several times (including once by us) so pay attention. The natural tendency is to attach the hood latch to the outside of the core support like was done on the factory unit. But that's not the way it was designed. On the bottom side of the upper core support rail there's a slot, and the latch inserts inside this slot. It's then bolted in place using the supplied countersunk bolts and lock nuts. Because of this, the radiator can't be bolted to the core support until the hood latch is in place.