ProMaxx Performance developed/designed this cylinder head from the OE casting 86TM. This is a direct bolt on cast iron cylinder head to replace your factory casting. Year: 1989-1992 Models: Bronco II, Ranger Engine Size: 2.9L V6
1990-1994 are the best years as they have EEC-IV computer like yours does
The 4.0l torque will eat up your current manual trans but it will work
If you can get the 4.0l with 4x4 manual trans(M5OD-R1) it would be better, your transfer case will bolt up to that trans
You need the engine and engine wiring harness along with the computer to do the swap.
With the engine wiring harness is the EDIS-6 module, located on rad support of 4.0l Ranger, front or back side, this is the Spark system so a much needed part, lol