[Jack Zupan]

My 427 has two fours with the S&H cleaner housings and K&N filters. I don't know the diameter but they are pretty small in order to clear each other. The depth is about 1.75 inches so all in all these babies are small. I dynoed the car with and without the air cleaners and saw no difference. I think the need for big air cleaners is sometimes overstated.

Jack Z.