Max boost for stock head gasket and arp2000 (425's)
#11
#12
A ported head will flow more but you also risk port velocity for port volume and WILL make your turbo lag until you tune it to run with the lower drive pressure ... but that being said too much drive pressure can be harmful and will cause high EGT's as well .. its a fine balance ... I would leave the head alone and work on other aspects of your build..