Rocker arms for 408 build

Thanks for the clarification. I think you have clarified that you do not have a viable suggestion for rocker arms on Magnum heads.
That is true, and neither does anyone else if they want correct geometry. That rocker doesn't exist, as I mentioned in my previous post. I can put just about any rocker on a head, as long as it will fit under the valve cover. Where it is located on the head is the key to proper geometry and operation.

I've done corrections to these heads using the shortest rockers I could find, and they still needed the studs relocated. The offset trunnions are the only thing that might work. I have viable options, but a bolt on rocker isn't one of them if it's going to be right.