If anyone was curious about the bare maincase, I found a thread on the moparts site about it. The 2801176 casting number was found in an old Petty Enterprises catalog and it shows the part number for the case.
The thread was on this site and can be found here:
http://board.moparts.org/ubbthreads/...page=&vc=1
Also here are the catalog pictures:
Thanks,
Jason