Here is another offering:
*** ONLY SOLD "BY APPOINTMENT" - EMAIL TO DISCUSS YOUR NEEDS. For OE replacement in vehicles listed see the complete kits instead - nothing else fits *** Shortcut to fulcrum chart Shifter base for custom conversions using Aisin AR5 5 speed manual transmissions sourced from: 2004-2012 Chevrolet...
core-shifters.com
I bought one of their shifters, with suitable pivot ratio, for my T56 magnum. The IS300 requires the gear lever to be ~2.5" further rearward, so I cut off the top of their lever stump (where it's flattened so you can bolt on your gear lever), and fabricated an extension to move it back the required 2.5", while keeping it as short (in height) as possible. My extension attaches to the "stump" via a 3/4" shaft collar welded to a piece of 1" wide, 1/4" thick flat-stock. I did have to make the hole in my transmission tunnel slightly bigger to accomodate the "tower" of the shifter base itself. I used a body saw to open it up the ~3/8" required and all was good.
I might add, the Core Shifter product is inexpensive and appears kinda "cheap". However, I had it all disassembled to modify for my purposes - and it is legit where it counts.
The product that Kris OK showed, which includes a linkage, is much better when the gear lever needs to move back in the car a long ways - say, more than 3-4+ inches, but if it only needs to move an inch or two, the extension method I used works just fine.