No it's not. Prior to 1984 (and from 1968) the part number for the door jamb switch was 14014578.
But the part number may not be the problem. Before you buy another switch, be aware that installing these switches is more involved than just threading it into the jamb - the extended length has to be set so that it matches the closed door gap.
OEM jamb switches from GM are adjustable. Not all cars/trucks have the same size gap in the door jamb switch area. To avoid having to produce a vehicle specific switch for every model, the switch is supplied with excess extension on purpose. The switch body is a press fit within the threaded bushing. The first time the door is closed, the switch is forced down deeper into the bushing - to a depth that conforms to the gap. By design, the switch body fit is tight to the ID of the bushing. This is so it does not move after the correct height is set. Consequently, it takes quite a bit of pressure to move the switch within the bushing at initial adjustment.
Read this:
Out of the box, a replacement switch may look a little too long when installed in the jamb, but it will self-adjust. The sleeve is very tight and requires a good amount of force to make it slide down into the nut.
You can also tap them down with a hammer carefully in a vise if you wish to set the height before the install. But, if you use a vise, make sure you don't over squeeze the nut.
and
Don't be concerned about the shoulder because once installed, gently close the door and longer shoulder-shank will press into the body.
Below is how setting the jamb switch should work. The top picture as it is right out of the box, the middle one after installing it - and closing the door to set the slide tube portion, and the bottom one shows an adjusted switch - with the door closed and breaking the female end connection ground.
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http://www.camaros.net/forums/34-restoration-corner/193474-door-jamb-plunger-switches.html
http://transamcountry.com/community/index.php?topic=61389.0