I'm out of 1 1/2" angle but I have a bunch of 1/4" thick angle 2"x 4' long cut offs. I'll make the top piece of each side and the mounting point from it.
I wanted to be able to turn it vb side up- just for ease of installing the front servo and valvebody. I thought it may be more balanced mounting it closer to the center of the trans. I may make a 2nd one for mounting to the bell face. This 518 I'm getting ready to start on only has 3 case tabs instead of 4. I have a 47rh I'm using for mock up
I might do one that way still. I'll see how I feel about this one when I have it all bolted up.
That picture lol is much better. From the first pictures I thought you were just using one side of the transmission.
That does limit your mount to that case specification.
Looks good and robust.