cars that are over square (like the b16 and F20c) are much more comfortable in high rpm. An oversquare engine is one which has a larger bore than stroke. Square is just that, perfectly square. The K20A is an example of that. Undersquare, like just about every other honda motor is when the stroke is larger than the bore. The standard LsVtec is slightly undersquare @ 81/89, as is the b20 block, but has a better ratio @ 84/89. As for rod-stroke ratio, you are correct about that, but is a different issue. If you had read closely I said I was only building it to rev to 9000, but I'm assuming that if I balance it to 9500 rpm it wont be unbalanced in the 9K range.