I use a custom 3"id dual intake system and have the filters in front of the radiator. I know it gave more hp per the dyno done this spring.......but it was achieved with some other mods so all in all was worth 55 or 60 hp over the stock tune, pulley and intake. I am working on moving the air intake to the back of the engine bay and customizing a cold air filter system similar to the cowl induction on the SS chevy's in the '70's for less travel distance and hopefully cooler air without going through the engine compartment as it does now. Still in the initial stages.