just a complete different engine, that's all...
you could maybe make your 200 into a 225 by boring and replating the cilinder and find a matching piston.
if you lack some power, just get the squish adjusted and you have a whole new engine (sort of)
i personally left my base gasket completely out and put some rtv instead and that made a world of difference.
if you do the same, i strongly suggest you measure at least if you still have enough squish.
i still have a squish of about 1.3mm and was 1.8mm before!
but it gave me more over the entire powerband
good luck, and stick with your 200, they're magic if you get them right
ciao, hannes.