well, all work is relative and depends on what you want done or what you want from your engine.
basically, head work is about sorting flow for the neccesary application. a full race head designed to purely flow as much as possible wont work very well with rd cams and std injection....infact, itll be poo.
same with a mild head, if you get it done to a limited spec, then expect what i can deliver, dont keep throwing in bigger cams and larger TBs.....itll just make it flat.
A rd head is about compramise, decent flow, but decent gas velocity to keep torque somewhere near the lower rpm regions LOL. And thats hard with the F7 head......keeping the velocity that is.
nothing special about the F7.......just know what your doin and you should be ok. BTW, where abouts are you?
BTW, are we talking OE manifold or one to fit throttle bodies?
anyway, the working of heads involve the removeal of material, amount depends on purpose and cam profile, and reshaping of teh ports to achieve the best flow. In SOME heads you can remove guide bosses that protrue into teh block if there is enough material IN the casting to hold it tight and take the heat away from the valve.
Its a very specific art, and ill show you some pics of people who DIYed it and tehn sent it to me......itll make you laugh...hehe