You really need to find out what your compression ratio is. That's the only way to find out what octane you need. You can have 145psi, but 12:1 ratio, so you need 110 octane. On the other hand, you can have 165psi, but have 10.5:1, so 93 will work for you. It all depends on ratio, timing, port duration, temperature, humidity, and elevation. You can't base octane needs on cranking compression. You need to know the ratio.