I notice some bumpers that you see the bolts on the face that mount the bumper to the frame (ala PureJeep), yet on others you can't see the bolt heads (ala Shrockworks), atleast that i notice in pictures. First why? Second, how do they not show the bolt heads? Are they welded inside of the bumper?
I am building my own and wonder if there is any benefits to this?

Second, what is the normal height on a bumper, front face top to bottom? I have cut mine to 6", but i am not sure if i like it.

 

I had some pics saved, but I'm not sure where they went.

Anyway, on the back side, they use a c-channel shaped piece that is welded to the inside of the bumper and the other side has holes and is bolted to the front of the frame rails. Kind of hard to explain, maybe somebody has a link to those pics.