Hi Dane,
Here's a place to start:
Ford numbers explained!
The number for the 385 series block is right above the starter.
There are basically three production 385 series blocks: The usual, the stronger, and the 4-bolt. They escalate in price accordingly. The difference between the "usual" and the "stronger" is that the main bearing webs taper to the pan rail, whereas the latter are flat, thicker and look more like the four-bolt ones.
There are also aftermarket blocks in both iron and aluminum is price is much less of an object.
Any of the 385 series blocks will support 600hp easily on the street as far as I know.
Hope this gets you started!
Tom