ok kool, the heads i have flowed over the years the gs-r had better mid range, but most were slightly modded so yeah maybe im wrong, i say this after u port a head, its done, if u want a new port configuration i's rather start with a new head, u never know what kinda secrects u can find, more alike when ur usin a street head velocity is key, but if u got a full race head and ur getting the fuel, thats when u can start opening up the port alot more