Really, that is a question I have asked a couple of times and no one seemed to know. I had started a thread asking if you were building a new engine that was rpm limited per class rules, which feature would take priority, bore or stroke with a 555 limit? The answer I got was typically bore size due to how large an valve I could run and still clear the bore. I was asking this on NA motors, so maybe valve size on a blown motor doesn't matter as much. So are all the BAE motors typically that way too? Most of them claim somewhere between 521-540 cubes, so I am very curious which way those are setup...