Knocking 340

AJ/FormS said
With aluminum tight-Q heads, some guys are claiming 200psi on pumpgas.

I dont even know how to equate that to CR. :D

Edit: thought about it and 200psi = 13.6-1 cr?

So 10.5-1 = 152psi?

Although Ive read an early 340 is not actually 10.5-1 but closer to 9.5-1.