You guys kill me with these stories of complexity and expense. The crank shaft can be brought to brand-new specs for $400, heavy duty rods can be had for $235, Wiseco pistons for $230, new Spec II chambers for $550 and the bike will scream! I've done 8 of them, 6 of those for my personal collection. There are more parts in a CB750 Honda cylinderhead than in the entire H1/Mach II or H2/Mach IV engine - it simply does not get any easier than one of these - unless of course you go to a twin or a single cylinder engine. No cams, no valves, no internal chains or tensioners, no valve springs, no keepers, no shims - I mean simple.
As for selling price - I have yet not to get all of my money out of the few I've sold. I will only warn that the correct, good parts won't come cheap - but that works 2 ways - the selling price is 3-4 times what a CB750 would be. Let me add that the price to make 150 horsepower on one of these H2's is a whole lot cheaper than getting a CB750 to make just 100. I've got twice in engine parts and machining on the CB836 than the stupid powered H2. I can only guess that Sparty's build would triple the H2's cost. You can have heart pumping, crazy power on these for $2,000...
Regards Gordon