fuzzy-hair-man wrote:
You can tell if it has an 1100 crank by rotating to TDC on 1 and sticking some wire down the sparkplug hole do this on no2 and the difference is the stroke

as for bore size I think you will have to take the head off

You are probably right about having to take the head off, but I would try shining a torch down each bore with the spark plugs removed first. Most oversize pistons have a marking on the top indicating their over size (+020,040, 060 etc). If you can find one of those markings visible, you may get an idea without having to go to extreme lengths. The downside is that it is on the flat edge of domed pistons right near the bore and may not always be visible.
KB