This depends entirely upon your location, the year of the car, the Engine, the transmission, the Rear end, and tire size. Theoretically, you could make a Falcon go 200 mph by putting a 427 V8 in it with a 7 speed Porsche transmission and large enough tires.
However: early to mid sixties falcons tended to have two speeds, capping at 55 MPH. Later, they had 3 speeds allowing for 70 mph. Then there's Australian models that can do anything a modern car can do since they're modern.
Ford XM Falcon was created in 1964.
Ford EL Falcon was created in 1996.
Ford BA Falcon was created in 2002.
Ford BF Falcon was created in 2005.
Ford XK Falcon was created in 1960.
Ford XE Falcon was created in 1982.
Ford XB Falcon was created in 1973.
Ford EB Falcon was created in 1991.
Ford XY Falcon was created in 1970.
Ford EF Falcon was created in 1994.
Ford XW Falcon was created in 1969.
Ford XD Falcon was created in 1979.