Eh. I think the mounts are weak looking and vibration will loosen the bolts if it doesn't crack the brackets themselves. I have the exact shape grille guard you do and my brackets are abotu 3/8 thick and have gussets.
I would look into running some 3/16 plate from the frame to the bottom of the grille guard to have a solid mounting point or you can use some heavy duty angle iron if you can make some nice clean cuts through the bumper vallance Or maybe they will fit through where the slot cut out is. you may have to fabricate a Z or S or some angle down and the back to straight and then bolt it on with two Grade 5 or 8 bolts per side.
Ok you see where the fog lamps you installed in the air dam are? Right behind that there should be the front frame horns. the bottom of your frame may line up with the air damhole. So you take a piece of 3/8 angle iron ( looks like a L shape piece of metal) bolt that to the frame and make it so it sticks out of the front of the truck. Do this on both sides. Obviously cut to desired length Now you will have two pieces of metal sticking out. there will be a flat side on top and a flat side either to the left or right depending on how you mount it. . The flat side of the Angle iron is where you bolt the grille guard to. if you cut the back edge of the upright brush guard metal structure to form fit to the way your bumper shape is you can get the grille guard to sit really close to the bumper ( basically youre making yourself the lower mounting pieces which look like are missing in your pics.
There is a special tool. I freaking forgot the name. it looks like a plastic square tube and it has a bunch of metal teeth running the length of the tube You press it against a shape and the little metal teeth move and as you press it you get a outline of the shape of the object you pressed it against. For the life of me I cant remember what it is and i have one in my tool box. it woudl work well to trace out the side view of your trucks bumper. then you transfer that to the back side of your brush guard and you cut off the area you traced out. This way the grille guard would sit closer to your bumper. Hope this makes sense.
You can always buy a cheap body line trace tool ( I think thats the name but not 100% sure) and then draw and cut the backside uprights of the GG so you can get the GG to suck in to the bumper and look like its made for your truck. Also the light guards look too wide ( not sure if it is or the pic angle makes it look like that) but they look way too wide for your truck. You can get a pipe cutter and cut a few inches off then reweld and sand.
Ok the part of the grille guard covering the headlights. You can remove the small 3 bar headlight guards leaving you with the headlight hoops. you can cut some of the tubing off thus essentially shortening the width of the grille guard to fit your truck better. its obvious the truck the GG came off of is wider than your truck. if you look at my grille guard you see that the ends of the GG where it wraps around are actually close to the edges of mytruck. Thats how you want your GG to look like.
if you were here in Cali I woudl give you a hand with it
You can make it fit and look great on your truck but right now I personally don't feel like its the right GG for your truck. Sorry man but it looks like what it is. A grille guard from a different truck bolted to another truck.
it looks ok when you first look at it but then you look closer and it just doesn't look complete or right.
If you liek the way it looks then ignore everything I just said.
not trying to be a jerk but you asked for true opinions