Not trying to get off of the original subject of this post....but try to straighten out the floorpan issue. 

 The drivers side power seat was an option beginning in '81. And yes the floorpan is deeper on those models to accommodate the taller track/motor assembly.

So if you choose to install a P/S in a non P/S car be prepared to lose a couple inches of head room.  

Sarge  

Thanks for the input. My seats are not power, and frankly, I have no need for power - I'm 6' 1" and already have the seat as far back as possible.  I'm just looking for a bit more comfort.