'308' vs 1976 360 heads

Of the stock 1.88 heads I’ve tested, the higher lift(from .400 and up) intake flow was better on the 308’s than others.
Not way better, but better.

The exhaust is okay ootb, but where the ex port shines is how much better it is with some porting, because of the filled in floor.

On the right type of build, they would be a pretty easy 400hp head(with some mild reworking) on a hot 360.
But...... if you’re paying to have it done...... they’d cost you more than some new SM aluminum heads.