When I first got back into ATC's I really wanted to find a way to make the 200's run like something they are not. It's the old drag race adage...there's no replacement for displacement.
If you NEED a bigger engine....GET a bigger engine. HA!
It does seem rather silly to spend tons of dough to make a 200 run like a 250. I'm sure SOMEONE out there can make a 200X run like a stock 350X..........But for how long?
I had a project in mind recently that I was going to end up spending a LOT of money on to be where I wanted to be. It would have involved a very pricey stroker crank, boring the engine case to accept a bigger sleeve......Then I realized how stupid I was being. For less money I could chop, weld and mod the motor mounts and put a 300EX quad motor in there. (I have a line on one locally) Everything else being equal, the later model 300EX would run circles around it...Reliably. Not sure If I will go that route but it sure makes more sense than squeezing the 200.
I was born and raised on Venus & I may be here a while.....