The back of the 250 is just the same as a small block, if it bolts up to the small block it will bolt to the 250.
A turbo 350 will work just fine, the 400 is a little overkill, and the 200 series trans has over drive.
Stay in the '70s when looking for car parts, the 292's were made up the late '80s in pickups and heavy trucks, so look there as well.
Your truck already has the better steering box, if you want power steering, then you will have make something work, nothing else will bolt in.
Be sure to sell your old box if you change it out, its a up grade for the older trucks.
Joe
Last edited by Joe H; 07/17/2010 1:53 AM.