but back to what you originally asked about (the cams). internals on both motors are the same so a cam swap wouldn't do you any good unless the other motor has upgraded cam's

in a straight line race the 323 and 325 will be pretty much dead even. the 323 is a little peaker across the power band where as the 325 makes a 'smoother' band, pretty sure the 323 makes a little more torque than the 325.