Update: So I bought a 5-blade, Mopar performance fan from my friend Jim. I also bought new crank and water pump pulleys from 440Source and Hayden's low profile heavy duty thermal fan clutch (I regret buying the clutch; I should have simply tested this using no clutch like what was suggested). The reason I bought a new water pump pulley is because the aluminum one that was on the car was so thick there was barely any space to mount the fan clutch and fan. I first tried used pulleys that I got from my friend. But the water pump pulleys that I got in the deal didn't fit (either hit the water pump or did not align properly). Also, the crank pulley that I got in the deal didn't fit because the balancer on the engine is modern, requiring the pulley with the offset. So, out of frustration, I simply bought new pulleys. Prior to installing everything, I spent a lot of time sealing the factory fan shroud to the radiator, using strips of neoprene that I attached using rivets and silicone to seal the bottom of the shroud, where a large gap (1.5") existed. The car was out last weekend at the Golden Super Cruise and it still ran hot; got to 230 while sitting in traffic. So, after all of this, I fixed nothing.

At this point I guess I can try the 7 blade factory fan. The Cummins diesel fans are huge and would require modification to fit into the shroud opening. My friend did have a large fan from a 70's Ramcharger; but way too big for this application. Regarding the suggestions of trimming down these large fans, I think the ends of the fan blades are shaped in a specific way (looks like it to me). If I start trimming them down, I will most likely disrupt the flow of air off of the fan blade tips.

Finally, I am not convinced that dual electric fans are going to fix the issue. My friend Jim runs a 500 on the street with 13.5 compression and a .700+ mechanical roller and the Mopar performance fan with viscous clutch keeps that "cool" (around 200). This engine is making a lot less power than that one makes. The specs of the car and engine applicable to this thread can be found in the first post of this thread.