Joe Lucia: Question on OEM vs Replacement Parts

[David H.]

On a recent thread concerning the availability of shock absorbers for a mid-year, you noted that while the specific part number was not available through AC Delco, the specific part number remained available through Chevrolet (as a Delco part).

Other than asking you, is there a way to determine the original part availability in the Delco system, or should we always just go to the Chevy dealer first?

[Joe L.]

Re: Joe Lucia: Question on OEM vs Replacement Part

Dave-----

I'm not sure that I understand the question. Are you asking about parts, in general, or shock absorbers, specifically? In general, if you go to a GM Franchised Dealer (any car line), they will obtain their parts through the GM parts system under a GM part number. Sometimes, they will obtain parts through the Delco parts system for common replacement items like filters, spark plugs or shock absorbers. In other words, a GM dealer can order you parts directly from GMSPO warehouses and can, usually, obtain Delco parts system parts through a local, independent Delco warehouse.

A local Delco parts retailer can only obtain Delco parts system parts through their local, independently operated Delco warehouse or other non-Delco parts from other aftermarket parts channels. They cannot order GM parts directly from the GM parts system.

Certain parts are ONLY available through the GM parts system, even though they are supplied in the same sort of Delco boxes that Delco parts are packaged in. These parts will carry a GM "long number", but NO Delco "short number".

Certain other parts are only available through the Delco parts system and NOT through the GM parts system. These parts always carry a Delco "short number" and may or may not also carry a GM "long number". Increasingly, they DO also carry the GM "long number", but these GM "long number" parts are NOT ORDERABLE through the GM parts system. For the most part, these are AFTERMARKET REPLACEMENT-quality parts and NOT OEM-quality parts. There IS a difference.

Sometimes, certain parts can be obtained through BOTH the GM and Delco parts systems. These parts carry both a Delco "short number" and a GM "long number" OR only the GM "long number" and are orderable through either parts system, but they are the exact same part. If obtained through the Delco parts system, though, they will almost always be less expensive. You can be sure of this: if the GM "long number" is the same on a part box/tag, even though the box/tag may also contain a Delco "short number", then the parts are the same. If the "long numbers" are different, then the parts are different.

Word of caution: when I say that the parts are the same if the "long numbers" are the same, I am talking about engineering specs. Various "nuances" not involving engineering specs or engineering specs which provide optional ways of achieving the spec, MAY be different for the same GM "long number", especially for parts produced in different time periods.

[David H.]

Thanks (I was referring to parts in general.) *NM*