Do I need to worry about valve shrouding in a 318 that is .030 over when putting Edelbrock Performer RPM heads or any other heads that have a 2.02 intake and a 1.60 exhaust?
And never worry about valve shrouding. While you want to avoid it for best performance, there's more than just a few factory examples out there in the world that have a bad case of valve shrouding but yet, the engine makes ridiculous power.
Oh! Almost forgot! David Visards has a good book on porting heads that has a topic on this issue. While the book is not an in depth technical book with hard to understand jargon, it is certainly worth the price of reading.