Sorry for monopolizing the forum. My head is spinning. Each answer opens up more questions.

So rather than rebuild my MC18, including scavenging parts, I am looking at a complete running MC28 engine. Will it run OK with the MC18 carbs, PGM I, etc.? Does this make sense for a track/race bike?

Specsheet says the 28 has a slightly higher compression but less power. I am guessing this could be because the top of the exhaust valve is a bit lower? If so is this in the barrel itself or a thinner base gasket? Are the barrels and heads interchangeable?

Is there some resource that lists all the combustion chamber, porting, crank case, timing and other detailed specs for the various models?