Canton Racing 22-595 install question

So on my 340 currently, I have the 90 deg filter adapter that goes on with the big hollow bolt. I'm going to be relocating the filter so I got the Canton adapter. I'm assuming that I need to pick up a short nipple and thread it into the block in order to use the Canton adapter?? Any old nipple will do? Should I use stainless?? Any advice?

Thanks in advance.