Hi there. I´m not 100% sure, but I´m pretty sure the combustion chamber on both M44 and M42 is 34cc, and the stock piston dish is 10cc
About the deck height, on the stock M42, the piston is 0,15mm above block deck. that is with 10:1CR, and stock block/crank.
Now, I see what your point is, (but correct me if wrong) building a 2110cc with street maners and keep it as stock as possible, (in measures)
Well, I don´t know if you are aware that the M47N crank needs a few mods to make it work, and also a custom made front extension. this would make the crank a two piece crank, which I´m not very comfortable with.
Metric mechanic makes this conversion but they will not sell just the extension.
I was over that dilema a few weeks ago, and finally opted for the M47 88mm crank and S52 pistons(86,4mm)
Very little modification to the front of the crank, and a 2 mm shave to the pistons will yield a streetable 11,5:1 CR, 0.5mm deck height, and 2044cc.
Also this crank is better counterweighed, and far more reliable than the M47N
I´m doing this to my engine right now, so if you have any more questions, please feel free to make them.
I hope this helped you.