Small block radiator & shroud

question, I have a 340 Duster 30 over 509 lift cam & all the other goodies, I’m going to replace the stock radiator with a champion 3 core, the old factory shroud will not fit the champion radiator, is it necessary to install the shroud? I know I have the option of running a electric fan behind the new radiator, on hot summer days in Michigan the temperature would be around 190-200 in traffic, will I see a difference in temperature with the champion and maybe a 160 degree thermostat thanks!!

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