Head Porting Question

[nwbaxter66]

Somewhat of a newb question, but I am about to get a set of heads ported and have read many threads on this and other boards that refer to Stage 2, 3 and 4 porting and preparation.  I have looked on several web sites - John Eales, V8 tuner and others and they seem to use different terms.
Is there a generally accepted definition associated with each term - I am not expecting that there is an ISO type classification, but would love to get a better understanding before I embark on my project.  In a post from last year Dan Jones and a couple of others were referring to Stage 3 and Stage 4 level work done on stock 4.6/4.0 heads and I would love to understand what that meant and whether it was transferable.

Thanks very much for any enlightenment or any links to posts that would answer the question.

Nick

[roverman]

IMHO, This defers to how much cash flow, you are willing to hemorage. Without specific description of  work and flowbench reports, for each level of spending, what are you really getting ? Porting is like swimming from shore. The further-out you go, the easier, to get lost. Good Luck, roverman.