I'm with mel. If your looking for a cheap and easy lighter duty 4x4 front end you would go with F-150 front TTB. I believe they will bolt right in. I remember reading in a 4x4 magazine where they converted a 92 or so ford f-150 2wd truck to 4wd. It was a bolt in deal on the suspension. I would use the f-250 coil springs for weight and dana 44 8-bolt hubs to keep the bolt pattern the same.
I have not done this but did a little research at one time and believe this all would mate up fine. If I do another 4x4 conversion I'm going to try this. My solid axle is great, but expensive and a fair amount of work. And I'm currently reworking with parts from 99 up superdutys.
Thanks,
Jeremy