Known overheat issues 4.7 RAM V8? EDIT FIXED

I never understood why they redesigned a new engine when they had the 5.2 and 5.9. Those engines were tried and true and lasted forever. Why not just them and make them better? They could have worked on the heads and intake and made some really impressive hp and torque with a tried and true design. Because as we know the bottom ends are damn near bullet proof.
The cam in head was the improvement!