May be a silly idea, but if you post on a tri-5 website you might just find someone who will give you a complete 6 cyl drive train out of 55-57 with all of the brackets, linkages etc. You may luck into an original overdrive. If you get these pieces and find a 261 it would be a very cool combo.
I am a later motor fan, but there is something about a 261 in a 55.....
