[Sheepdip]

Here's a couple of pic's that I took for you as best I could. As stated mine is a 1 ton cab n chassis so the frame rails are a straight 34" od.

On the out side frame work (left pic) the 2 bottom angles that you see the ends of also sit on top of the frame rails to support the downward tongue weight.

The 2 top angles support the actual hitch just under the bed deck. The uprights with the angle welded between them are 1/2" X 4" flat bar.

The 1/4" X 3" flat bar you see running down at roughly 45 degrees is welded to the top rectangular tube and bolted to an existing hole on the truck frame, there is one on the other side that is not seen behind the tire that is fastened the same except it is straight up and down, this is typical both sides.
This is the only welding I had to do after everything was in place and tightened down.

All angle iron was 3/8" X 2" X 2" I prefabbed everything to make it a bolt in application.

Like I said earlier I got the young bucks over to do all the muscle work and drilling of deck and the 4-1/2" holes each side of the rectangular tube that sits on top of the frame............. Cost me Pizza and Beer.