It's why tuning is such a big part of making this stuff work. I prefer the higher compression ratios for other reasons than just power production. It also helps in the vacuum department, throttle response, drivability etc... with a cam well matched to the combo it'll run pump gas relatively easily.
Matter of fact I built our DZ 302 with a true 11:1 compression, just as the factory rated the engine. Using the original iron 186 hump heads, and the original DZ camshaft. What helps this combo work perfectly on 91 pump gas is the 30-30 camshaft as it's often referred to. 254 degrees @ .050, and a wide 114 lsa in a very small 302 CI engine. Lots of overlap. Been daily driving this thing now going on 3 years with nothing but crappy 91 pump gas here in AZ and it runs perfectly with 36 degrees of total timing. Ask dad, he'll tell ya it flat gets with the program for a little engine.
A camshaft like this needs compression anyway. If I were to build this engine and knock the compression down thinking I needed to do so to run pump gas, it would be a complete turd, sluggish throttle response and just an all around pooch to drive.
But again, to make this deal work, you need to have pretty good tuning abilities and good control over the timing and fuel curves. However once that's dialed in, you don't have to touch it. About once a year I'll check the valve lash for good measure, that's it.
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