If you put the 440 avs on the 383 and put a good set of valve springs on it so it will turn the rpm needed to match the 440 air flow. Put a 3.91 gear in the 383 and a 3.23 in the 440 to match the power curves. You will be surprised how close they are.

There are exceptions to every rule, sure the over cammed 360 will run better as a 408. You have a hydraulic cam and can't turn enough rpm to meet you heads limit. In both those cases a 408 will run better than the 360.

The point I am trying to make is don't think you are going to take the heads, cam, induction, and headers off of your well matched 360 put them on a 408 and make 13-14 percent more Hp. If you do there was a problem with your 360.