SuperHO is right. You need to cut, at least, 2 1/2 in from the center of the handle to bring the shifter back to its original height. Then you put the handle back together with the collar.
A muffler shop could do the work for you easily, both the welding and the cutting.
The hard part will be cutting the inner and lower shifter brackets to fit the aluminum body through the floor pan.
If you cannot do it yourself, pull both brackets out and send them to me. I charge $25.00 to cut them in my milling machine and $10.00 to ship it back.
Cutting the actual floor pan is very easy once you get the brackets back. You can use them as a template.
Of course, the SHOrty Shifter kit was intended to be installed by do it yourselfers. It is not a dificult project if you have some basic tools.
Jose