Proflow Transmission Fitting Adaptor, 1/2 in. NPT To 7/8''-18 Inverted Flare Union, For Ford Auto Pan Fill C4/C10 Dipstick, Each - PFE665-NPTPart Number: PFE665 NPT These Proflow C10 pan fill unions wil screw into aluminium pan tapped with a 1 2 npt thread to allow dipstick tube to screw in. Will work with both genuine Ford dipstick tube as well as all aftermarket tubes with inverted flare and oem 7 8 18 thread. See Instructions for hole size and postion to drill and tap your case fill pan. If you need to convert a pan but want to convert the easy way, please look at PFE665.