If you ask me 73° isn't too bad, but let's see if we can bring it down a little. If you have over-volted the CPU, try lowering the voltage just a touch. It might still be stable on a slightly lower voltage, & the good side-effect is usually lower temps.
It wouldn't hurt to keep the GPUs a little cooler too, so adjust their fans so they kick in sooner &/or spin faster. You may get a little more noise, but at least they may not shut down as often. G