Redundancy and Overkill time, (best reasonably priced thermostatic cooling fan)

Ive got a 360 magnum nicely warmed Over, about 390 hp.

Cooling situation:

Twin electric fans, set up with an electrical thermostat set at 180, with manual bypass switches on rheostats ( Thanks Rusty Rat Rod).

Hi vol water pump

Biggest Friggin radiator I could fit in, its touching the corner if the battery.

Custom stainless. Shroud being made by my buddy who owns a sheet metal shop.

Question
i have plenty if clearance, the electric fans are pushers. How should he design the shroud to not make it a major frig to change the fan, and at the same time not have Excessive clearance that reduces the effeciency of the fan ?