Is it worth it to port L92 heads??

[scherp69]

I have a stock L92 that I will be putting into my 68 Acadian(Nova). I plan on running a Mast Motorsports SS cam, their controller, Stainless Works longtube headers and a 102mm FAST intake with a 102mm Nick Williams DBW throttle body. With that set up, I hope to be around 550 - 570 hp. What I'm wondering though....would it be worth it to have my heads ported? How much of a gain would I see and what price range would I be looking at to have it done? Also, is there anyone that you could recommend, preferably in Canada or West coast if possible. Thanks in advance.