Very hard to answer such a question. Depends on how good the person is whom is doing the job, how restrictive the head is in the first place, and how good the person is whom is doing the job. If you aren't changing runner, or valve size, not as much. That is OK though bigger runners aren't always a good thing. I think if the head was all you did you MIGHT see 15 or 20 IDK I'm just guessing. It sounds like you have a good plan, and you should see some nice gains. Are you going to the dyno after everything is done? I think it is interesting to hear about someone taking a non fast car and making it fast.
Good luck!!!
