[Mike C]

I would think just getting the correct flywheel would be all that it took. 168 tooth for a 7.4l externally balanced with correct bolt pattern for your year. Everything else should be useable. You might be able to run the big block on the small block mounts which keeps the trans in same spot. You will need to build a custom z bar (crossshaft).

If you go to big block mounts, you need those for the manual trans bellhousing as well since they are moved up and to the front. They are not so common... Also need clutch pushrod from pedal and appropriate cross shaft.