Is the rebuild your only option to consider? If you source a good replacement engine you may save costs. I bought a complete project truck, 1954 3600 all disassembled for $1600 with this fresh rebuilt 54 235.
http://www.flickr.com/photos/advance-design_parts_co/8129067943/in/set-72157631867396207
I then sold off the remaining parts and made most of my money back. If you are looking for the original rebuild I get that to, just a suggestion if you have some flexability.