1996 Ford 460 V-8 Metric or standard

I am installing gauges: Mechanical oil pressure, water temp, volts and vacuum. I would like to Tee the oil pressure and keep the original sender in the loop. Does anyone know if the sender threads are metric or standard so I can obtain the needed adapters while awaiting delivery of the gauges? OBD-1 if it matters. It seems many fasteners are metric, but not sure about senders.