split port are hard to port due to the funky angles and the way the ports are made....if you get a good set of heads teh intakes should add 14rwhp and 10-12rwtq with upper alone with both not sure. it is pricy though. check out www.rpm-mustangs.com cuz they have a good price on all that stuff around 1500 for all of it including a cam. (plus core)