From looking at his sig, it looks like he has stock heads, and a Performer intake, neither of which will be very good at making power, especially on a stroker. You can use your stock heads if they are ported, but the Performer just won't cut it. If you can find a used set of aluminum heads, or a set of iron performance heads, that will probaly cost less than porting the stock heads and having them redone.
I live in a place where used aluminum heads are nothing but a good dream, let alone getting a good deal on a set. So, I'm "stuck" with a set of 351W heads that I found in the trunk of my car. With some DIY porting, and a little visit to the machiene shop, I should have heads capable of supporting 450hp, but I would have gotten a set of used aluminum heads if I could.
So, I'd say a 351W stroker might be $200 more than a 331/347, but you'd get more power out of it. Besides, there ain't no replacement for displacement

HTH
GTRaptor said:
If you go the 351 route you will need better heads, headers and a 351 intake. So it will be more expensive than using a 347 stroker.