After a couple hiccups with the relays for my MSD system, I installed a derale electric fan and automatic fan controller. There fan is rated (and I'd say probably pretty accurate if not understated) at about 2200 cfm and comes with a cowl attached. The automatic fan controller is awesome and has an A/C override circuit as well. The fan fits the '66 radiator like a glove and is very easy to mount. It was relatively cheap and easy to do. The fan controller PN is 16749 and the fan PN is 16926. They sell a mounting kit which I found to be redundant as the plastic pieces that come with it do a good enough job in my opinion.