1991 Performance

I know you can man up the 1992 supercharged engine in a Park Ave better than a 91, but is it any performance parts for a 91?? Is it possible to do an engine swap??

It suppose it is possible, but it is a lot of work. I have heard the engine can be chiptuned to gain about 15 hp. Performance ignition parts can also get you a couple of extra hp.

I suggest calling Summit Racing. They seem to have all kinds of things for anything. But, if you are not wanting to replace the motor, or make major and costly modifications, which you don't really need anyway, just remember the basis of any power upgrades fuel+air=power. I would go with this list -

Fuel
bigger throttle body
bigger fuel injectors
replace the in tank fuel pump with one that bolt along the frame

Air
K&N air filter/cold air intake
look for superchargers from the Ultra models

Spark
Aftermarket coils
8mm wires
Iridium spark plugs

Start there