Originally Posted by Silver Surfer
For comparison, here is how L31 engines left the confines of the General's compound with 87 octane friendly specs...
Also, take into account that those specs were only compatible w/87 octane in large part due to the ECM's ability to sense and quell detonation on the fly. These same specs, if using an analog ignition and carb, can still easily get you right into detonation if max power timing is used.
Get the quench optimized, but do not try for that last tenth of a point of compression- the gains are tiny (a rule of thumb often quoted is 4% per full point of compression, or a 16 HP gain w/a 400 HP engine for going from 9:1 to 10:1, all else being equal) especially when compared to the headaches that a detonation-prone engine combination causes. Leave leeway for a bad tank of fuel or a minor overheating condition so such an occurrence doesn't park you w/a toasted engine would be my advice.