Dean,

Sounds like you've thought this out pretty well. 1" is a bit tight, but if you have a full coverage shroud the air has only one way out, through the fan. For the discussion, the fan doesn't serve much purpose when the car is moving because a ram air effect is in play, that's why I say a multiple fan application has the possibility of being more obstruction than solution. The fan(s) earns it's keep when the vehicle is stationary.