mac shorty headers on E7's or GT40's - fitment ok?

[fiveoho]

just wondering if a set of mac shorties bolted up to a set of ported E7 or GT40 heads will work fine? will flow be decent? any bottlenecks?

i guess i already know they will be fine on ported E7's just not postive on GT40s

reason i ask is bc i read a post of someones aftermarket head choice and the exhaust ports were not much better than stock. someone suggested a different set of headers other than what he already had.


thanks