HIGH FLOWING PORTED J HEADS

That said, those 5 cfm could be 10-15 horsepower. Some guys would kill for that kind of gain.
True depends on what your doing, In a highly competitive race class all those little things matter a lot, in a weekend burnout machine that may occasionally see the track not so much.
I know Pro stock stuff is huge bore. Give me a bigger bore any day of the week
There's definitely no advantage going smaller, but if we all cared that much everyone would be building 400/440 :)