I need to install vent tubes on my 1979 CJ-7's Dana 30 & AMC 20 Diff's, T-150 Trans and Dana 20 T-case. Currently there are no vent tubes or nipples on any of these pieces and I have never installed vent tubes before. Basic question I have is how to attach the vent tube to each of these components. I see the vent holes on top of the Dana 30 Diffenential and the passenger side axle tube of the AMC 20, but neither appear to be threaded. So, what is used to secure a vent hose to these holes, drive in copper tubing or is there a fitting made for this? There"s a vent button on the top of the T-150 and I guess that's where you attach a vent line, but where is the vent on the Dana 20 Tcase located and how do you attach a vent hoses to it?

Thanks for any help.