Looks not good for the swap;
Matt wrote on this;
"The engines are significantl different with just about no interchangable parts.
The 2.8L is a lower HP carburated version while the 2.9L is a multiport EFI
version with better HP. (In '86 the 2.9L offered 140, very good for its day.)
The 2.9L was a major step forward for Ranger pickups and unless you are
planning on a V-8 engine swap in the near future, I'd hold out for an '86 or
newer.
Matt"
& I believe the 2.8 bell housing isnt the same as the 2.9s
Look here for better swaps;
http://broncoii.org/techpages/index.html
& Body parts, etc. check out my Bronco site in my sig for many parts; search by key word for what you need.
GL!