Best flowing big block heads?

An engine builder I know told me that the 915 heads I have on my 400 will perform better than a set of Max Wedge heads.
The reason is that my current build does flow enough volume to use the big ports of the wedge heads. He also said that these 915s with the work(porting) that has been done to them...they will support 650hp. So the current 475hp these heads should be fine. I dont know if this makes any difference but the block has been zero decked and heads surfaced given me right at 10:1.