Any of those three casting numbers would be fine, but don't rule out #670, #12, #48, #061.
The only thing wrong with stock parts in the bottom end are the rod bolts. Nothing else in there is at risk with a 350 like the one you are trying to build. 1.5 ratio roller rockers can be added without any other changes or mods.
Just keep in mind that if you swap out the heads, you owe it to your car to give that 350 a little more cam, too.
