Dude! You never said it was IF! Thats why the front threads are straight on that bulkhead fitting... but the o-ring is ghetto, even though it will work for a "vent".
get one of these:
Screen Shot 2021-11-15 at 10.26.57 AM.png
and put whatever length MPT extension you need in it. Mmmm, close nipples....
Screen Shot 2021-11-15 at 10.29.02 AM.png

I swear one day I'll be the crusty old guy that works in the fastener section of an Ace.