Just came across this. Might come in handy for someone. http://www.hammar.dyndns.org/~djhamma/partnumb.htm
I agree. You can look at the prefix & suffix of the # and usually figure out what year, model & design change of the part. GM part #'s were always a mystery to me. Can any of you GM guys shed a little light on GM part #'?
nobody on this site cares, but VW was pretty good also - first three digits denoted vehicle style, next three were cl*** of part type, then on to the specific part number.