5r55s 2006 mustang gt

I have a 2006 mustang gt with a 5r55s, I'm currently building the motor and since it's out of the car, I thought I might as well go through the trans. That being said, I'm aware that these are not designed to hold much power at all, so my question is. What have yall done to make them more bullet proof? Currently I only plan on boring the cylinders and adding some cams. Later on I may add boost, but that's only a possibility. I would be producing right around 500 hp with everything. I will be getting a stall converter as well, just not sure what stall speed yet since I haven't fully decided on what cams. Thank you for you advice!!