....No, what I was saying is; I would LOWER the compression ratio AND plan on using the 92 octane gas. The 400 small block that I had ran aluminum heads, had 9:75 to 1 compression AND I used 91 octane {that's the Max octane in Calif}{.... Remember the new cars that have compression ratios in the 10 to 1 & 11 to 1 range have; aluminum heads, fuel injection, computer controls to retard timing {knock sensors}, combustion chambers that are designed for low octane/higher compression......