Fred - the major difference between Ebay and a big swap meet, other than holding the item in one's hand, is that one SOMETIMES has recourse through Ebay.
The phrase is still very much caveat emptor!
For awhile, one of the major aftermarket companies was cloning the Q-Jet, and putting their own number on it. While I have not personally inspected one of the Q-Jet clones, their reputation is less than wonderful.
EDIT: also, during original production; GM commissioned Carter to manufacture millions of Q-Jets under license from GM. Carter also was granted authority to offer Q-Jets with the Carter number as aftermarket. If it is a Carter, the number would be the typical 4-digit followed by the letter "S" (eg. 1111S). These carbs were produced to the same quality and calibration as their Rochester counterparts, however, few individuals have a copy of the interchange list.
Jon
