not sure that would be useful - one might be fightin the other - I'd say either or how close is your fan to the rad, and is it fairly centered, or down towards the bottom? needs to be quite close otherwise a shroud helps] and somewhat centered
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics