So, you're wondering which would come out on top on a dyno; given similar strokes, bore sizes, valvetrain (I assume by that you mean similar cam specs), similar "decent" aftermarket heads, and overall displacement in the same general range... They're going to perform pretty similarly.
Sounds like NASCAR.
Yeah, Im with you. But there's enough of a difference in a real comparison using real off the shelf parts that there would be differences. I'm curious what those would be.