TH350 in 69 Camaro I’ve seen a number of posts that say there should not be trans fluid in the tail housing however I found this port which looks to be machine and fluid is coming through there. Which is right should there be fluid in the tail housing? How does it circulate back through the main body? Photos attached.Will appreciate any advise

 

so long as its not coming out threw the seal at the driveshaft yoke your good. I have always found a small amount of oil in the tail housing. makes a mess every time I take driveshaft out while removing the trans. if possible I leave it in until trans is out. gotta wrap black tape over the universal joint caps so they dont go flying.