The Holley pan is designed for the motor to be forward. No idea on the Milodon pan though.
I mocked mine up with the Holley pan before I had my k-frame welded and gusseted and was going to add a 1/4" or so notch. I just had the motor sitting on the k-frame with the motor mounts and the angle of the motor could have been off, but it wasn't actually touching the k-frame. Close enough that I wanted a little more clearance but not enough that it wouldn't have bolted in.