I just got done cc-ing my 727 and I've come up with 11.74:1 as the compression ratio(which sounds spot on since the CP piston is rated at 12:1 and my combustion chamber is actually larger than stock because Kenz modified it to unshroud the 1mm oversize valves). So here's the question. What's the limit of 91 octane pump gas? I'm actually planning on running 3 base gaskets(to help out my close piston to valve clearance) this time around. So my compression should end up being right at 11.0 to 11.25:1 when all is said and done. Anyone think that's still too high for 91 octane?