Got a tranny temp gauge to install and it didn't come with the adapter http://www.autometer.com/cat_accessoriesdetail.aspx?vid=66 . Sounds like my probe is 5/8"-18 UNF. I plan on welding in a bung into my tranny pan to install it. I could get one of these to make it easy http://www.autometer.com/cat_accessoriesdetail.aspx?vid=64 but I want to install it tomorrow for a run on new years day and prob can't get one in time. Can I just get a 5/8 fine thread nut and weld to my pan and install or is that adapter something special?