If you are going to use a shim, adaptor, spacer or any other fudgin'-it device, and it's location is critical to safety, it should be high quality and strong. Interestingly, there are a bunch of crappy shims, adaptors and spacers out there that are dubious at best.
Luckily Nitto understands that testing and manufacturing a product so that it's safe, is important. Cold Forged, off-road safe, and heavier than other versions of the same thing 'cause they're strong!
Nitto makes a number of these. There's a number of quill lengths, and diameters of shafts + quill diameters. Email us to acquire one 'o these, and to be sure you get the right one for your needs.
Our favorite usage of these is to put LD stems on Riv's, super hot!