Hi, I have a problem I can't seem to find any info. on & was hoping to find some help here. On my 97 K1500, the vent tube on top of the rearend has rotted off & I can't tell if it's threaded in or not. I have looked on numerous sites for a replacement tube & they have them for other makes but nothing for Chevy. I don't want to do any drilling without knowing what size or how they're put in. I would appreciate any advice-Thank you