I do not remember where this part came from. Does it look familiar to anyone? 1990 5.7 1500

 

It's got an O-ring, so it's from a sealed system. Vacuum port?

 

what did you work on?

 

1990 Chevy 1500. Think it may be from transmission. not sure. If my pops was still around he would definitely know if it was a trans part.

 

Where did you find it? Is it threaded internally where it's covered up? The top, can't really see from here, but is threaded below the end cap, or is it hollow?
That detent? I think it's a plunger housing for your transmission.