They came in 2 port sizes IIRC. Small runner and large runner. The small runner I hve on a shelf. Theports are standard sized at a gasket match to the Fel-Pro's 340/360 gasket.
Those batten heads will make a S/B sing a mighty song. More displacement the better.
i got those batten heads and going to put them on my 400ci sb mopar with a f1 prcharger from the supercharger store we r looking to make from 900-1000hp on pump gas streetable.