Matt Bachand
Depends on the 6.5
Here's the cover I made for mine, ran it all winter in to the spring and the truck never got hot, it seemed to warm up a little faster in mornings, and held it's heat a little better too.
It was just a piece of laminated cardboard spray painted black, I left a little opening around the bowtie for some air, and I made little tabs that slide in next to the headlights and then zip-tied it around the hood latch. The only drawback to it was that when we got some sleet it was junk.
Someone stole your bumper holes bro! You be running 'round lookin like a gasser! I wouldn't even wave to you if I saw you!