FYI, I used a 3 core 22" Champion with a 16 " electric fan mounted to the radiator and no fan bolted to the factory water pump on my 68 Barracuda 416. I cools great.
I tyried that on my 505 to styart with, it didn`t keep it cool, went to a mech belt drivern fan w/ a booster in front , now adequate, but would still like a hair better. Maybe ur 416 isn`t way up there in h.p., it creates more heat.