Searched and couldnt seem to find the answer I need. Putting some VDO oil press and water temp gauges in my car and need the npt thread sizes for the oil pressure and water temperature sending unit threads on the engine. Could just buy the kit with the adapters, but its like $10 cheaper to just buy the sending unit itself with the exact thread size. On summit's site they list them like this: 1/4-18 NPT, 3/8-18 NPT, 1/2-14 NPT If anyone knows the exact sizes, I would really appreciate it. These stock gauges are driving me nuts!!!!!