Magnum shortblock capability.

What can the stock 5.2/5.9 shortblocks handle? Power and RPM?
Also if one was to change just pistons to something lighter and add some better rods what could the oilingsystem and stock cranks handle in these engines?

Just thinking some here, considering that these engines are very affordable and possible to go oldschool on,not a full build just throw cam and compression on the thing add a good intake manifold and a set of headers and let it scream like one would have done to a 340 back in the day.
Edit: if changing rods and pistons a balancing would of course be required,but keep it real basic.