Here is the correct gear for your application. Note that not all gears are the same even though many sellers
state 67-75. Not true.
http://cgi.ebay.com/ebaymotors/NOS-MOPAR...sspagenameZWD1V
Concerning your parking problems.
1) Could be a bad ground on your dash switch. Since your motor works it is not a bad ground on the motor.
2) Bad dash switch. The circuit breaker inside the switch maybe be burnt or defective.
3) Front switch plate on the motor itself is not making a good contact. Make sure the brass tang inside has a good
pressure and contact is clean.Make sure outside wires are soldered properly to their respective posts.
4) Blue wire connection on firewall or plug is not good. Check wires for breaks or oxidation.
Please do not ask me to sell you a gear as I need them to earn a living restoring motors.
Thanks
Jules