Well after a lot of "guess" before, I got back under the truck and did some actual measuring. What I discovered is this is not going to go quite as smoothly as I hoped. First off, the angle will actually fit right between the two rail bolts, and not under one as I had hoped.
Here is a REAL picture of a piece of 1.25x1.25 angle I stuck up there just to test.
It does align with the center hole in the bracket, but I am seriously not knowing a way to get a bolt in there from the top. The hump in the rail sits right over that hole and I would have to unbolt the entire hitch rails to get a bolt in there.
By the way I also discovered with the goose neck center section in there it will be darn near impossible to reach the bolts above the fuel tank. They were incredibly hard before, but the goose neck REALLY blocks the access I used to have.
This is a shot without the test angle, and this is the wide open side.
Also a shot of the center section in position. The 1x2" rear rails is on the RH side of it.
And the bed with the center section in place. At least it LOOKS like it will function. (edit, forgot to mention, you can see the center bolt that I moved from the rear hole to the forward hole)
This shot of the outside shows nearly everything. To the right is the 1x2" rear rail, and center are the 3 factory holes I will be using. The left and right holes will be for mount bolts and the center hole (driver side only) will be for the release rod for the turnover ball. My thumb is pointing where the farthest rail bolt is positioned on the other side of the bracket.
It looks like I will be back to the "Z" bar idea, unless someone here has a better idea (other than forgetting the whole idea).