I forgot to mention the fan spacing wasn't good either. What actually caused the fan blade to bend was it hit the bottom edge of the upper tank before cutting into the core; there's a noticeable gash in the tank from where it hit, about 1/2" long. I have another factory viscous-drive fan but the clutch is too thick and hits the rad core; I'm going to swap the fan itself onto the current clutch which is still fine and add a washer or 2 on the back side to space it farther back just a hair.
Oh and the motor mount didn't technically "fail", the two biscuit halves are still stuck together but about half of the rubber has torn away from the steel. So basically since getting the new engine in, every time I romped on it the mount would tear a little more and let the engine move a little more over and over until this happened. I was dumb and should have checked it before it would have been so easy, I could feel a weird "thump" when getting on it hard which I now figured out was the engine falling back down on the k-frame. Oh well, 20/20 hindsight and all, once I get everything fixed and back together I am definitely going to test out the new mount with the hood open and load the engine up against the converter to watch how much it moves.