[750hp]

Les - if you're going for the traditional crank stroke to get the cubes you're talking about, I wouldn't be concerned about the difference.
3.75" stroke for 377 cubes
3.85" stroke for 393 cubes

The 3.85" stroker package is cheaper, because you use standard spec 302 pistons. I'd personally choose the 3.7 or 3.75" crank, but I believe your block will easily handle any stroke up to 4.0" without any probs at all...