With the 2hp per cfm rule of thumb, 293 cfm = 586 hp, now it can make more than 2hp:cfm but if it making a lot over 586 hp your probably under headed.
If everything here is getting you well under 2hp:cid eg.. 475-500 hp with the 293 cfm/586 hp head the 325 cfm might not add anything or not much, if making 550-600+hp the 325 probably add a decent amount depending on cam.
if making well under the 325 hp 2hp:cid probably effects throttle response, but probably make the 293 cfm heads hp + with lesser cam, which makes for worse driveability large cam or heads?.
Richard Holdener has tried to find out if you can over head size and flow on the dyno, he has found bigger generally don't lose power but there's point where gains are smaller and smaller to not at all, but as for real world performance and driveability that question is still up in the air, with a 416 I think you have less chance of side effect especially if 550+hp is the goal.
