Helmet - Bazooka
Head - Kickstart
Body - Ret. Mouse
Vest - Ret GIJoe Trooper
Grunt, to me, was just a boring action figure and character. He just never stood out to me as toy, except for his Falcon Glider version in the tan uniform. I really liked that variation. So, this custom is slightly based upon the Falcon Glider variant.
Grunt is just a basic soldier who eats, sleeps, and breathes Army which is what makes him an essential member to the team. I think Marvel kind of alluded to this when they portrayed him as still performing PT early in the morning even after retiring from the team.