jkane, go check out my first post in this thread and follow the link. It will show you the best place to cut the frame. I chose this location because the frame rails are straight and a piece of 5" channel will fit inside them. I just bolted the 5" channel inside the frame for right now because I want to get the body, bed and front end on the frame so that I can center the wheels in the fenders. Once I have the body mocked up, I will take it all apart and weld the frame and the 5" channel all together. It should be plenty strong that way.
Frank
PS I've had to put the 46 on the back burner. I am painting a 55 Ford (yeah, I know, it's a Ford) for a friend. He brought just the Cab, fenders, hood, running boards and bed assembly over. So when I get it painted I will get back to the REAL THING, the 46.