Do you plan on using the 2.8 tranny with the 2.3 or not? If so a bellhousing swap will have to be done along with the using a 2.3 clutch, flywheel. If using a 2.3 tranny then should be fairly easy in out. You will also have to swap motor mounts to, 2.8 are different then 2.3. If your 2.3 you plan on swapping in is fuel injected then you will have figure out how to get fuel to the engine, either go with aftermarket fuel pump or use factory setup (tank swap along with use of factory pumps).
Why swap out the 2.8? If its due to the computer setup on the 2.8 then you can get rid of it for a duraspark setup and if it has oil burn to it then the valve stem seals may need replaced. Theres a good write up on the valve stem replacement and uraspark setup in the tech library.
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