If you maximize compression by choosing your billet rod to be .020" over-length with a flattop piston, and using a .010"-.012" head gasket, use a billet flywheel with rare-earth magnets and higher spark advance coupled with an advance key to reach about 36-degrees spark advance, use a hi-perf coil (resistors disabled to prevent spark retard at high rpm), use a .265 intermediate cam, add a pulse fuel pump, use the right venturi-type intake adapter with a hi-flow air filter, use a header pipe without a weiner muffler, put in .022 low jet and .036 main jet, upgrade to 22# valve springs, delete all of the components inside and out that make up the governor, delete the oil sensor inside, adjust valve lash int/exh to .003", use Royal Purple Break-in Oil from beginning to end, then you'd be approaching 14 hp. Remember, all that power will only come in at the high end of your rpm range, that's why 420cc are great, their torque kicks in at the start line.
Can't guess what the list you gave would make, and I have zero experience with the 301cc or the new Ghost engines.