Like mine
I made a set out of peg board backing with foam and Back Pack grade cloth pulled over the top and stapled to the back. Black plastic caps cover the holding screws and they indent the padding just enough to look real sharp.
Easy to remove with 2 wing nuts per insert.
Cummins recommends a certain amount of air flow for the intercooler. Call them at 1-800-diesels and can tell you how much. I count the holes in my front bumber as sufficient air for the intercooler.
Ran mine without the fan last winter and really liked it (quieter, and a bit more HP).
With rescent mods and towing more this year, I don't dare pull with the fan removed. If it were to start overheating, the fan would be back home in the garage. I never had a problem towing last winter with the fan off, but I was bone stock then...