There are two ways you can go with that setup. Since it was not designed to use a traverse leaf spring you need a way to bolt or weld batwings to it that will mount the spring and the radius rods too. RPM has a kit to do this modification.
Or, you can remove the 56 axle and spindles and substitute a 28-48 axle and 37-48 spindles, and use a simple bearing swap kit (that Speedway sells) to put that all together. This is a cleaner setup, appearancewise, and all you would need to complete the setup are a couple of batwings and hairpin radius rods, or a set of split wishbones from someone like Speedway.....or you can split your own out of early Ford wishbones. With this setup you can either mount the spring over the axle or suicide style, and people like Posies sell the correct length spring to make it all work out.
As for the steering box, that one is the one most rodders like to use and I have one in two of my cars. Not used so much in T buckets because of the way they mount and the fact most T bucket steering columns are almost vertical. The F100 box is usually mounted in front of the firewall, not under the floor.
But if you can pick this whole thing up reasonably there are some very good parts there. What is he asking for it ? Reason I ask is so we can tell you if it is a good deal or not.
your right on the 28-48 axle don i think ill just use some piese but get it all from him im going to see if he will take like $125 for it all hes a good friend and old phone guy
john
Don