It does matter which head you start with. You can't just open up any head to the port shape you want. Valve to head angles differ, port heights, water jackets etc. There are some basic proven things you can do to any port to improve flow (pocket port, 3 angle valve job) but to really understand what is going on you absolutely need a flow bench.
A good book to read (even though it deals with chevys) is by david vizard. I think it is called "modifying small block chevrolet cylinder heads". There is a lot of basic port theory in there.
