What is causing engine knocking during acceleration in high gear with standard fuel and correct timing on a 94 Park Avenue Ultra?

Timing is controlled by the PCM, and is not adjustable. You might have a problem with either a plugged gas filter, egr system malfunctioning, or induction problem (leaking tube going from the MAF/MAP to the throttle body. Also check the PCV valve. In addition, carbon buildup. Most supercharged vehicles require premium fuel only. Also, engine pre-detonation (knock) is sometimes a symptom of high exhaust back pressure. You might have a muffler shop check the back pressure in your exhaust. It could be a plugged up catalyst.