409/409

Does anyone know the correct part number for an 1975 L-82 4 speed built at the end of May???
Thanks in advance

LeMans Pete

Hi 409,

7817575 is the part number supposedly used for the entire 1975 model year with a backing plate 7801149.

Now, if you look at the revision block of the 1975 A.I.M., you will see that it appears there may have been 3 different smog pumps used throughout the year. Early (rev. date 11-7-74) '75s would have possibly had the '69-'74 pump, PN 7803948. A 2nd revision on 4-5-75 is illegible, but would have possibly said "was 7817575" and changed to the pump typically seen on 76+, PN 7817809.

If this is for judging purposes, use the 7817575 w/ the backing plate 7801149, as this is what is currently expected. Since the judging manuals are continuously being improved, not that in the future this may not be correct. I say it may not be correct because production line changes do not necessarily follow the revision dates on the A.I.M. and it would be entirely possible for your car to receive the 7817575 pump.