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 ?
By "pusher" fans I assume that they're mounted in front of the radiator? I mounted my fans on studs so I could remove if necessary. Also the fans will lose efficiency very quickly the further they are from the radiator fins. Ideally they should be mounted dead up against the radiator, also there should be so way for air to get around the fans or shroud, this will cause cavitation.