......well I don't believe there is a compression ratio to octane 'chart'. There are way to many 'variables'. Plus two engines built exactly the same could react differently to the same octane. Different shape combustion chambers, quelch area, alum/steel all affect this.If it were my motor I would not go with a 10.88 to I compression ratio with iron heads. Why take the chance??? Now here again there are no exact figures but I've read that you have a 3% HP loss for every point that your compression ratio is lower. If your motor were to put out 300 HP with 10:88 to 1 compression then it put out 292 HP with a 9:88 to 1. Your not going to feel that difference in a seat of the pants feel. Take a look at the GM crate motors. The iron headed 350's don't go over 9.40 to 1. Even the aluminum headed ones don't go over 10 to 1 {I just pulled these examples out of a the
www.SDPC2000.com catalog}...... bill