Are you are wanting to improve performance of a machine that has sluggish or weak flippers, jets, etc or lights flicker when a solenoid fires? I had both on my 1978 Phoenix machine, with a new pintek power supply which I don't recommend. However, I pulled existing capacitor, put in 8 10,000uF caps and it operates great now.
The easiest and cheapest upgrade is to replace or supplement existing PSU capacitor(s), depending on age as electrolytic don't live forever. Put in about $8 of caps, rated about 50-80mF. Just get voltage and polarity correct.
The driver board may get hotter since it *may* dump more current, so check temperatures too and add a fan prn. 5" at bottom of back box.