The shifter on my T5 came up about 10 inches further back than stock. Follow below as you see what I did to make this work.
BTW - A tremec transmission with the mid shift kit has the shifter in the stock location but I only discovered this afterwards.
This first shot with the tape measure shows you where about the shifter is going to come through.
Here you can see the T5 with the transmission tunnel cover removed. I have a 2x4 between the frame rails as a temporary support.
Here's the area I cut out. I had to make a U shaped steel plate to fill the back area.
Here the plate is welded in.
To cover the existing hole I cut a sheet of aluminum to size.
After pop riviting the plate I sealed it with some body cork.
Here's how it ended up looking. Notice I put the shift handle pointing forward since it sits quite far back.
Another view. The shifter I used is a UPR Blue Thunder short throw shifter.