351c 2bbl heads?

IM thinking about buying a set of rebuilt stock 351c 2bbl heads, I was wondering if having them milled or using stainless valves would make much difference in power? The cars gonna be mainly a street car, whats the most power I can get out of a set of 72' 351c 2bbl heads? Im adding flat top pistons so I should be at 9.1 to 1 compression before the milling.

Thanks
Jim

Thanks for the reply's. Im thinking now of going to 4v heads, I hear the torque isn't as good for street use but even the stock specs on the heads still produce more torque then the 2v heads? The again alot of people are telling me although I'll get the HP I want out of the heads it will be high up in the RPM's and wont do much good for me on the street. Will a stock 4v beat a stock 2v off the line and for the first 100 yards or so? Aussie heads are my other option but they seem to sell for over 300 dollars and thats for a bare set not including valve jobs and springs, i'd probally run way over the money I have to spend.

Thanks,
Jim