I thought about doing that when I was welding and bracing my frame on my K5
My machinist used to have friends running Nissan x-Terra's. They have a steering box that looks an awful lot like a scout II Saginaw box -mounts to outside of frame rail, but the box itself is on top of rail, so the sector shaft is longer than a Chevy box... The braces he made had a bearing of some type that went between the pitman and the cast iron on the box. He said it was more to keep the box from premature wear and leaking, than to protect the frame/ vehicle.
I ended up not bothering with it on the k5, and just put the brace on the back side of the box to the crossmember.