ledslinger29":201076wd said:
Given the wealth of information you guys have so generously provided. I'm thinking about maybe just biting the bullet and taking the whole bottom end back apart and get it decked down .050. I had time to do a little better measuring tonight, and I'm getting .052 on all cylinders. If I get it ground down .050 and stick with the Felpro gasket I should be a hair under 9 on the SCR, which will give me power but hopefully keep me out of the danger zone. I did som looking around for 170 cranks, and they all look pretty rough or are more expensive than getting the block decked. But keep the advice coming, I've always got time to make an informed decision
If you go with a victor gasket it is .044" compressed. I have build many engines & the Victor seems to weep less from the drivers side.
195# cranking compression is the max on 93 octane fuel.
The following is a copy & paste from an article on gasoline.
Octane ratings explained
So now we know what engine knock is and how to prevent it. We are ready to look at how anti-knock properties are measured: octane ratings.
There is only one way to measure the anti-knock properties of a fuel: burn it in an engine and see how much it knocks. Obviously, fuel companies don't just tip samples into the gas tank of an old Camaro and drive around listening for the pinging sound. They use special engines which are precise scientific instruments costing in the region of a million dollars each! (The exact price isn't advertised, because if you have to ask, you can't afford it.) These engines allow scientists to precisely measure the amount of knocking caused by a fuel, but they need some kind of standard scale to compare fuels to. This is why the octane rating was developed.(Some rights reserved)
The octane rating isn't really anything to do with octane, but rather its cousin iso-octane that we met on the previous page. (So strictly speaking, an octane number is actually a 2,2,4 trimethylpentane number, but octane is less of a mouthful.) We have already seen how iso-octane is an excellent fuel that is highly resistant to detonation due to its compact, branched structure. Therefore scientists created the octane rating, where iso-octane scores 100. At the other end of the scale is a fuel that scores 0 (zero), and the fuel chosen for this end of the scale was heptane (C7H16). Heptane is highly susceptible to detonation as it consists of 7 carbon atoms in a long, flimsy string. By burning the fuel in a special engine, chemists can measure its anti-knock properties and assign it an octane number relative to mixtures of heptane and iso-octane. There are a couple of different ways to calculate octane number, but they are outside the scope of this guide. Normal unleaded gasoline has an octane rating of around 90 to 95 depending on where you live and the exact method used to calculate the rating. (Fuel that scores 90 octane in North America would be considered roughly 95 octane in Europe due to the different calculation methods.) Gasoline with an octane rating of 90 has the same anti-knock qualities as a mixture of 90% iso-octane and 10% heptane. Octane ratings higher than 100 are possible, as some fuels have better anti-knock properties than 100% iso-octane.
You might wonder what the octane rating of actual octane (known as n-octane) is, as it is even longer and flimsier than heptane. The answer is, bizarre as it sounds, that n-octane has an octane rating of -10 (yes, minus ten!), and is therefore an extremely low-octane fuel. In fact, n-octane has such atrocious anti-knock properties that it is present in pump gasoline only in small amounts. (Gasoline isn't a simple mixture of iso-octane and heptane, but is a carefully blended mixture of various compounds.)
Once scientists had created the octane rating, they could use it to test all fuels, regardless of what they actually contain. In other words, the octane rating is a measure of anti-knock properties, not of the octane content or energy content of a fuel. For instance, ethanol (C2H5OH) has excellent anti-knock properties and has an octane rating in excess of 100. However, ethanol contains less energy per gallon than iso-octane. LPG also contains less energy than gasoline, but is an excellent fuel with an octane rating greater than 100. Similarly, it is possible for two fuels to contain virtually identical amounts of energy but have different octane ratings (n-octane and iso-octane are an excellent example of this as they contain almost identical amounts of energy but there is an enormous difference between their octane ratings).
There is no point using fuel with a higher octane rating than the engine was designed for. So long as the fuel doesn't cause engine knock, it's good enough. Some cars are optimised for higher octane fuel, but can run on slightly lower octane fuel by electronically detecting knock and delaying the spark timing, at the expense of power output and economy. You should use fuel with the octane rating recommended by the car manufacturer. Flex fuel cars that can run on either gasoline or an alternative fuel such as ethanol or LPG must make a compromise, as an engine designed to run on high-octane alternative fuels would knock when running on normal gasoline. Modern, turbocharged flex-fuel cars can alter the boost from the turbocharger to suit the fuel being used, giving good power and performance on both fuels.
Summary
Engine knock is caused by fuel molecules breaking apart and detonating before the flame front in the combustion chamber reaches them.
The engine will be irreparably damaged by the shockwaves from this detonation if it is allowed to continue.
Designing an engine to reduce knock tends to reduce its efficiency and power output. Using a fuel with good anti-knock properties allows designers to squeeze more power and efficiency out of the engine.
Compact, highly-branched fuel molecules tend to be more resistant to knock.
The anti-knock properties of fuel are measured as an octane rating, with zero on the scale producing equivalent levels of knock to heptane (very poor) and 100 being equivalent to iso-octane (excellent). Pump gasoline with an octane rating of 90 has the same anti-knock properties as a mixture of 90% iso-octane and 10% heptane.
Octane rating does not measure octane content or energy content of a fuel, only its anti-knock properties. A fuel with low energy content that contains no octane whatsoever can still have a high octane rating.
Note, the different ratings in the USA vs Europe.
I think you may be off some on your piston to deck height measurement, stock they were about in the .019 to .025 range. In any case you would probally gain better results by Zero decking the block thereby tightening the quench area instead of cutting the head down more. The ideal quench is about .035 to .045 so with the new style gaskets you would be right in the ball park if its Zero decked. Good luck on your build 
If you were to deck it to near zero and have ~.045" quench, you may be able to safely go to 9:1 SCR or better. I have no problem with saying you'll be fine @ 7.5-7.7:1 DCR. You're in Florida and it gets hot and humid. The last thing you want is to have to dial back the timing b/c you're pinging the damned thing. It will just get hotter.
