which end goes up for brass collar on the jet needle?

In picture
cdn.partzilla.com/MTE/d/b/MjA0NjAyMg-b191b246.png
...there is a part labelled #4 , "NEEDLE JET". It's a brass collar which the jet needle slides through, before it gets down to the emultion tube and main jet.
I did not mark it before it fell out, so I am unsure which end goes up when I put it back.

It's sort of a "barrel connector" shape, or a brass collar with a a "stop ring" around its middle to set how far it can be inserted. It has:
- one end, slightly shorter/stubbier, 0.205" outer diameter, narrower inner diameter
- other end, slightly longer, 0.196" outer diameter, wider inner diameter

(sorry, can't measure the inner diameter well)
I can slide it over the jet needle all the way to the plastic slide, no matter which way I turn it.

My _guess_ is that the end with bigger inner diameter goes up, and narrow inner diameter goes down (to be parallel to the sloped sides of the jet needle), but since I didn't mark it, I wanted to ask.

EDIT: I put it on the end of a Q-tip, and can only insert in one way: the skinny end (0.196") goes in, but the fat end 0.205" doesn't want to.

Look at the others.
Steve

The emulution tube #5 did press and center the brass collar into the port. The slightly longer, 0.196" outer diameter with wider inner diameter goes in first.