Over the winter i want to turn my 502 500hps into 540ci what is the best way to do it.

You are going to need a new rotating assembly. And a new cam and then be ready to have someone remap the fuel curve in the computer.

What is your goal?? That is a more important question. Looking for more speed?? I would say save some money and just have them freshened and spend the coin on a cam and some head work and then remap. Those motors already have a nice crank and rods, why change them.

Send it to me.

What are your goals? How much power? How fast? What is your budget? The answers to these few questions will dictate your build. Give us a little more info and we can steer you in the right direction.
Eddie

Mine are carb motors, head work was done in the spring im running a 741 cam, but the bottoms have 460hrs on them.

Call Ateco. They do this all time.

I have a 489 stroker, same thing only bigger pistons. You need a 4.25 stroker crank specific to your version of BB. New Hbeam rods. Have you block bored .030 over with the correct forged pistons. Re-map your ECM, RM builder cam would be the best. Your cam would probably work fine but your RPM range would probably a little lower.