Sorry if I posted this in the wrong place. I figure you Mustang guys know the most about these motors.
I've been trying to ID this motor for awhile and I found this:
428 Cobra Jet Flexplate Identification
If you look at that flexplate, mine matches the SCJ plate:
428 flywheel | Flickr - Photo Sharing!
Besides the 1U crank, I haven't found anything else to ID it. Here's some more pics:
Block casting | Flickr - Photo Sharing!
Exhaust manifold | Flickr - Photo Sharing!
Intake C6AE 9425-G | Flickr - Photo Sharing!