Bores for the different capacities are:
215ci - 3.52" - 140bhp/200ft/lbs
245ci - 3.76" - 165bhp/235ft/lbs
265ci - 3.91" - 203bhp/262ft/lbs
Obviously this is in standard form, there was a 218bhp/273ft/lb version of the 265, still with 2bbl Carter, while the Weber-fed engines gave 248bhp/306ft/lbs or 280bhp/310ft/lbs or 302bhp/325ft/lbs depending on which version you got. Which outstripped all the V8s offered in the Australian models.
It's also the case that some engines (for cars intended to be raced) left the factory with overbores... not sure whether they were 0.030" or 0.040".
