I just bought some Hilti expanding foam from Home Depot. It comes in a red aerosol looking can. Make sure you wear gloves and work slowly. It's easy to get overzealous and have it expand more than you want, 'cause it can expand quite a bit.

Even though I only slightly modified the rebar (I believe it was my write-up that was mentioned), I used foam for extra reinforcement around the oil coolers, signal lights, and around the main radiator/intercooler opening. The styrofoam that's on the middle nose part of the 93+ bumper seems to be sufficient in preventing sag of the top middle section.

 

thanks...how long have u had it installed? does it hold up good over time and everything? well im guessing since its probably for insulation or something it will...hehe yeah i`ll have to get some. probably play with it first to get an idea of how it expands thanks for the heads up there.