273, the good points

Does the engine have to be an actual 273 block, or just 273cid?
I wonder if the block would survive an overbore to say; 3.91? or 4.00?
I wonder what the shortest stroke crank a guy could find/ build.
I wonder if its possible to build a 273 with a bigger bore/ shorter stroke
Lets see, I seem to remember a short stroke crank from back in the TA haydays.And lemme see,I wonder if the machine shop cold find me some appropriate bigger bore sleeves. Hmmmm