Since you have the heads reworked already and are so high on the compression, you could look at replacing the rotating assembly with maybe a 4.25 stroke crank with BBC 2.200 rod journals and h beam rods for more cubes and lower cr.

With a truck being heavy you really don't want to run a loose converter as you will just be creating heat cooking the trans and maybe the engine also because of heat transfer in the radiator. I would also run an aux oil cooler on the engine. Stay away from pusher fans mounted in front of the radiator because all they really do is block airflow to the rad.
Does the truck still have fuel tank behind the seat? you might want to think about using an aux tank in your fuel system so you can switch back and forth with fuel grades. Get an KN extreme top plate for your air cleaner and a 800 or 850 holley carb(or 950 with vacume sec