When I go to start the vehicle, the starter stays engaged, and cranks even after I turn the key to the off position. Any ideas. Also where is the ignition switch located(not the lock cylinder)!!! Thanks

The ignition switch is located on top of the outer jacket of the steering column, near the firewall. It is actuated by a linkage rod from the ignition lock cylinder.

Another possibility is the starter solenoid sticking/contact welding.

On my 79 I was going through starters like bad hair styles due to shimming issues. When you purchase a new starter if you end up needing one, making sure they come with the new shims could save you a head ache later. If the starter solenoid is not the issue than hopefully this is good info for later :)