I'm not so sure about that. I just looked at some crash sheets for my 1968 Olds and there are tons of six-digit part numbers that couldn't possibly be dealer-installed items (like the gaskets between the fenders & the fender extensions, and various sheet metal pieces). There are tons of parts that have 6-digit numbers. Maybe that rule only applies to Chevy. It's certainly not a GM thing.
John Nasta
-----Original Message-----
Hey chuck, does the 6 digit rule apply to all part #'s or just the later years?
Yes, as a general rule they are. Not to say there aren't exceptions...
Chuck
Perhaps it applies only to the accessories? I just re-checked my dealer accessories parts lists ('46-'78), and they all have six digit part numbers. The numbering system doesn't seem to follow any pattern that I can determine either... for instance a rear bumper guard for a '78 Nova carries part number 347564, while a '78 full-sized Chevy has 371979 and a '69 full-sized Chevy rear guard is listed as 993505. I guess, then, that the possibility of the "99" prefix meaning a "dealer installed accessory" isn't 100% valid.
Checked my "regular" parts manuals, and yes, there are quite a few 6-digit part numbers in there.
As I said before, there are likely exceptions. Perhaps there's a GM parts counterman on the list who can shed some light on this? Rich... any more thoughts on the numbering system beyond what you've already shared with us?
Chuck
