I have a 16" pusher and added a 16" puller on the other side of a 24" rad with a moderately built 440 in my 66 Coronet. The first 16" puller was not quite enough in summer, but two is a little over kill. I can sit in 100+ summer traffic and it never gets over 185 now. I'm going to switch to a 195 thermostat someday...