ok i just put in new piston rings and rod bearings in my ls,my question is how do i break them in?thanks

 

Bearings need no breaking in.

The rings need to be loaded up but not revved hard for probably a few hundred miles (others might disagree as to how many miles before hard revving is safe, some might say more some less).

To load the rings you need to get substantial pressure behind them to push them out harder against the bore than just the ring tension alone will do, or you might glaze the bores. As soon as you can after getting the engine running and timed etc, take it for a run. Once up to temp accelerate full throtte in short bursts through the gears keeping the rpm below about 3000, but otherwise drive it normally (i.e. more like your mother not how you might normally drive).

As you get some miles up over a few days gradually increase the rpm to which you allow the motor to go. In a week (more or ess) you should be able to rev it right out full bore with safety. Some peope might think I'm being a little conservative on how long before you rev it hard, but better safe than sorry.

Thus is just what I'd do, I'd imagine there are plenty of other ideas out there.