I wouldn't limit the stroke to 4.15 if you are trying to maximize cubic inches. The 4.250" stroke cranks with 2.2 rod journals fit better and give more CID. And as CAB said, you can have a 4.3x stroke made and it still fits pretty easy. Going all the way to 4.5" gets tough in a low deck (400) block, but fits the RB (440) block easier.

As for bore size, the most common (for good reason) is 4.375". You could go to 4.380" with little difference. The limiting factor, IMO, is the durability when the cylinder walls get thin. So sonic check the wall thickness and only go as big as needed, not as big as possible.

4.375x4.375x3.14159265/4x8x4.250 = 511.12 CID
4.380x4.380x3.14159265/4x8x4.250 = 512.29 CID
4.380x4.380x3.14159265/4x8x4.300 = 518.32 CID
4.380x4.380x3.14159265/4x8x4.375 = 527.36 CID