Re: ac delco
Case by case basis. "AC Delco" is a HUGE parts supply and acquisition branch of GM. They source parts from any country and manufacturer you can name.
For instance, the AC Delco boxed Platinum spark plugs for our engines are sourced from DENSO in Japan, as do many sensors. Most fuel injection system parts come from Robert Bosch, Germany. Thermostats may be Dayco, Stant, Gates, others. I have two "AC Delco" Northstar water pumps on the shelf - one from China, one from the U.S., probably Gates. Bose sound systems with a GM label. ......... and on and on and on.
You need to use a leap of faith to assume that an AC Delco boxed part will live up to the GM parts contract specs ........
AC DELCO - 1900's - 1920's: Albert Champion (sound familiar ?) + Dayton Engineering Laboratories COmpany