[Larkbill]

AC Delco can be from from two different lines, consumer and dealer. The consumer line is available to both parts stores and dealers, and the dealer's catalog typically has a line across the listing where the oem line ends and consumer begins. Thus often the parts guys refer to above the line and below the line. The dealer line is not sold through parts stores and is more often than not identical or equal to the oem parts. Usually the dealer is supposed to use only the oem line for warranty work, but may use the consumer line to be competitive with local shops. In batteries the oem line is called Professional Series, just my two cents, but the consumer line batteries seem to have less issues, like loose and leaking positive posts. On top of that they have a higher cold cranking rating.

Brake pads are a whole different cat. There's no longer a hard line between oem and consumer. Sometimes you can tell in the catalog, sometimes you can't. Sparkplugs are really all consumer, and some of the AC boxes will have NGK or Denso plugs if that was the oem equipment, but you'll find these in parts stores too. I've been away from it for two years, started driving trucks after I got tired of getting laid off, things have probably changed some. But I'll bet not much, the General doesn't like change. We used to note the country of manufacture on the boxes just for grins, oem and consumer were from all over, even north Africa. As I recall a bunch of the blower motor resistors were from Algiers. Didn't know they made anything there.