Does anyone know the maximum cubic inches you can get out of a 502 dart block? What would be the best way to achieve it?

that depends on your deck height..9.800 ? 10.200 ?

with the race series tall m you can go as high as 11.100,max is some were around 760 ci..

If it is a 9.8" block, then you can go to 565 ci. That is a 4.25" stroke crank, 6.385 rod and a 4.600 bore with a 1.27 comp. height piston.
Eddie