General question on race headers-Nhra rule

Ok it's not that I would do this but is it legal???????? Can u according to NHRA rules for Pro class-turn headers around and run them straight thru the hood????? I can find nothing that it would be illegal to do????? All i can find is that they have to be directed away from the driver,Well if they are straight out of the hood in a way they are--Thanks Guy's Steve