The advantage of Bill's set-up is the source of the vacuum would be close to the core on the left side, making a plenum simple to construct (add an extension tube out the front).

Chris, this is a good idea. I have only one caution, you would have to use a larger cool pipe than I drew it with to pass ALL the radiator air thru it. It IS possible but a different layout would be needed. Perhaps a partial ducting would work, say 1/2-1/3 of the rad, while avoiding restriction at high speed. High speed operation is the biggest problem with augmented exhausts.