Head Recommendation
Find out what they [your W2's] flow now, then have them ported and flowed again on the same bench.jmo
ps...what the other guy said about going to the next w #, like W9's, they flow [ported] in the mid 300's like 345'ish or so cfm.
but see what you have cause those heads [ported] will flow 320'ish cfm.
as for advice....look at the post history of thee 'advisor' and you can tell who 'knows' and who 'blow's'... hot air that is.