What features/specs does the 1997 Ford Crown Victoria P71 (police
package) have that the regular version of the 1997 Crown Victoria
doesn't have?

I can't give you all the details, but my  father has the police
package unit and everything on the suspension is HEAVY-DUTY! When I
went to replace the brakes, I found that the parts cost mucho dollars.
I have never seen rotors and pads that thick on an automobile, but I
guess they are expected to slow the car down from 100 m.p.h. to a stop
in a matter of seconds. I know the engine is larger size, and I figure
that the radiator and trans cooler are larger capacity too. The tires
and wheels are also larger on his car. It gives a great ride,
especially at high speeds, but be prepared to spend more bucks on
replacing those treads also.