How does this part attach?
 

Toyota Part # is SU00300890 - RETAINER SUB-ASSEMBLY, CONTROL SHIFT LEVER (FOR FLOOR SHIFT)

Looking at using a Twins' trans in a non-Toyobaru application. And I'm a little confused looking at the parts diagrams.

I'm guessing the circled part (part#330506 in the pic) attaches to the chassis in the trans tunnel somewhere?

I'm guessing this keeps the Shift lever (part # 33575 in the pic) stationary. Is it important in keeping the alignment to a certain spec? For example, keeping the shift lever and control shaft parallel to the driveshaft or transmission axis?

TIA!

It is bolted to the trans tunnel at the back just above the driveshaft output.

As per schematics shown 2 bolts SU0003-00005 it gets bolted to transmission tunnel wall extrusion. Here is thread for installing aftermarket one.

It's almost like an exhaust hanger for the transmission, but it gets bolted to the body. Here is an install guide that might help you see how it goes in.

https://www.ft86club.com/forums/showthread.php?t=19767

Thanks for the responses and links all. Gives me an idea of how to implement a solution.