You'll have to remove the park housing from the trany.
PARKING LOCK CABLE (SELECTOR LEVER END)
The parking lock cable operating lever on the selector lever assembly rotates on a cammed pivot similar to the one on a push button box. The position of the parking lock cable operating lever is adjusted, as part of the assembly procedure for the selector lever mechanism, to establish the correct amount of parking lock cable travel.
parking cable
To make this adjustment, proceed as follows:
1. Place the selector lever in "Reverse" position, and loosen the cam jam nut on the pivot.
2. While sighting through the opening in the left plate of the shift mechanism housing, rotate the cammed pivot until the scribed line on the gear selector cable control lever bisects the parking lock lever guide pin.
3. Hold the cammed pivot in this position and tighten the jam nut to 95 inch-pounds.
parking lock cable adjustment
PARKING LOCK CABLE (TRANSMISSION END)
The procedures for parking lock cable removal, installation, and adjustment at the transmission end are the same as for conventional TorqueFlites.
THROTTLE LINKAGES