The problem with the Falcon (and others of those years) is the 17-inch radiator support opening. With a radiator core only 16+ x 17, it's hard to find a factory dual electric setup that small. The larger 24-inch "big block" core radiators will fit Contour and Taurus-type dual setups, but the extra width is of little benefit unless the support is opened-up. Still, a wider radiator will get the same flow as the old one, so the width is wasted (unless the support is opened) but it will get the same flow as the old one from the old opening. I wouldn't run a wrecker's radiator, but new replacements for something close are out there cheap, such as '87 to '04 Jeep Wrangler.
If you can't run a mechanical fan, and you need duals to clear your pump, the wider radiator or a pusher setup would be options. Check carefully for clearance off each side for the BB rad, and you'll need to use different rad brackets to install it. I have a thread here somewhere showing a set of brackets I made for an aftermarket aluminum rad, and there are a number of ways to do it. Again, wrecking yard alternatives are there for the looking, such as late-model V8 Mustang.
I would suggest a universal 2-row aluminum radiator with 1-inch tubes. A double-pass version would put both the inlet and outlet on the right side for easier plumbing if you have a pre-'70 water pump. Alternatively, a GM-style setup with a top-left and lower-right will do well if you don't have belts in the way of your upper hose. If you have a '70+ water pump, then a generic Ford/Mopar-style (top right, lower-left) should be easiest. Any of these options should be under $150, to as little as $75 for a new universal radiator. My 2¢.
David
