Frank,
The only conversions I have seen on here use the whole S-10 frame. As I recall, the wheel base is about right. All you need to do is make brackets to support everything.
After having my 46 down to the frame, I don't know that the section you are leaving helps you enough to make it worth keeping. My $.02 would be to keep the S-10 frame in one piece and use as is. Keep the 46 frame in one piece and use it to determine what needs to go where etc.
Also, use the search function above...there should be quite a number of topics on here regarding S-10 swaps.
