I don't know how his Camaro is, but this is all there is to an aftermarket shifter for my car. Never heard of anyone lengthening the bottom of a shifter...
Lengthening the bottom of the shifter BELOW the axis point is what qualifies it as a "short shifter". With RWD's you have a problem with the driveshaft so you can't make it too much longer though. Shortening the top actually makes the throw LONGER.