It would run just fine. Sure it would develop some leaks, but I doubt the inside of the motor is rusted up. These motors were sealed up a lot better than the muscle car era motors were.
True story. Back around 1990 or so a friend bought a 1970 Torino Cobra that had been parked for 15 years, outdoors and uncovered. A bunch of water leaked in through the shaker scoop and made its way into the oil pan over the years. We pulled the pan with the motor in the car, cleaned it up, pulled a couple bearing caps and they were fine.
We put it back together with a new fuel pump, plugs, wires and points, swapped the carb off my car onto it after flushing out the old gas as best we could. With a little ether we got it running, and actually drove it. It ran like shit, but well enough to do brake torques.
And there was a water line in the oil pan, and on the crank.