Mbogina you have good points and I agree, but maybe I stated my logic a little odd. If I go back to the mower engine that is modified with intake and carb whatever, and now it wants to no load spin to 5K instead of the 4K no load, well then we have more power, certainly torque at 4K when we didn't have any before. So overall the engine makes more power. So building an engine that wants to no load spin to say 10K, but we shift and gear it so it never goes above 7K is all better than an engine that no load revs to 8K. I guess thats my point. The "about 10%" rule is one I made up after years of noting HP and Torque figures from racers. That certainly doesn't mean all motors are that 10%. A friends nail head Buick is a good example in that it was 325 HP, but like 450 in Torque. They don't call them nail heads for nothing. SO I guess what I am saying is that typical race motors fall into the 10% rule of thumb. But its only a rule of thumb.