Your not listening to me but whatever.... So what issue are you having with squish... What's your problem?

 

One of the things you are forgetting is that the formula you are using only calculates the flow requirements based on RPM and displacement. It doesn't take into account that the motor can only draw air on 1/2 the stoke..

From what I've seen a HSR42 will flow about 290 cfm at 28 inches but you put it on a stock manifold and flow drops to 250 cfm at 28..

If you want to correct pressure to flow multiply the current flow by the square root of the new pressure over the old pressure.

In you case the air filter will flow 200 x 4.32 = 864 cfm at 28 inch H20. Plenty there but that is at 28 inches. That means that filter is dropping pressure so the carb and heads see less pressure.. Less pressure means less flow.

Still they only way to really tell what the intake flows all together is to bolt it all together and put it on a flow bench. If the head flows 280 and you install the 42 and manifold, you'll likely find that the flow has dropped to something like 220 cfm..

If it were me and wanted to use all SnS parts but stick with the 42, I'd use the 79 cc heads, flattops, squish set to 0.034 and SnS570 cam.. I'd probably go with the 5cc domes and a Tman TM590 tho you could use the Sn585.

 

Easy start cams or not, your ccp does matter, because if it's too high, you'll either need to retard the ignition timing or run high octane (above 91 certainly-maybe even higher) fuel to avoid detonation. CCP is a general indicator of working cylinder pressure, not just cranking resistance. Seriously, you need to take this into account before you build your engine or you'll probably never get it to run to your satisfaction without either 1) risking engine damage or 2) taking it apart and doing it right the second time around. Just my $0.02 worth...