Maybe a different approach is needed.
Instead of an inline twin, something more along the lines of a RGV250 or HD V-twin.
Once the custom built case, crank, and stronger transmission/clutch was sorted, the only issue at that point would be to design a set of pipes for clearance.
Room would have to be made inside the frame, but let's be serious and ask ourselves how many guys would buy an engine like this and NOT put it in a fully custom built drag frame.
Furthermore, if we're going to be serious about it...the amount of money spent on such a built could easily buy a RGV500 or an all-out banshee drag engine, both of which would probably be a better choice.
No, the name of the game in the LT world is getting up to a certain aftermarket banshee build for half the money or less.
Getting equivalent power gains for an LT to be top dog in the 2-stroke world is not an economically sound decision.
You'll spend more money on an LT to be competitive than you would on a banshee or perhaps even a 250r.
In other words, if you want to really go fast, buy a different engine platform to sink money into and the returns will still be positive.