As you have read without knowing a lot more about your 460 it is next to impossible to give numbers on hp and tq. If all you are doing is freshening up your 460 the overbore will add very little other than bringing the engine back to what it once might have been.
The 625 will work fine with stock internals,our 460 for example has a custom built 1000cfm dbl pmp Holley it works as good as we hoped but the engine is built for it.
460 Ford Forum will be a good place to visit as well