Adding a pusher fan.

I have a 16" on the front of my '73 with a four core Champion. According to what I have gleamed a four core requires a pusher as a puller can't pull the air well enough through the width of the deep fins whereas the pusher reportedly can.
I`m running a 28x19 crossflow, 1 1/4" 2 row, 17" mech. fan w/ a home made but great fiiting alum. shroud. also have 15" elec. fan mounted in front of the rad., set to come on at 200* not a whole lot of time on the fish, but seems to be ok so far. ( no clutch)