AN MD-80 DEPARTING MMMX TOOK OFF OVERWT BECAUSE CORRECT WTS WERE NOT ISSUED UNTIL THEY WERE AIRBORNE.

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THE MMMX STATION PERSONNEL WERE UNCHARACTERISTICALLY DISORGANIZED AND RUSHED DURING BOARDING. EVEN SO WE WERE SLIGHTLY LATE DEPARTING THE GATE DUE TO LATE PAX BOARDING. OUT AT XA54Z. TAXIING AT XA55Z RECEIVED CLOSEOUT. MAX WT FOR TKOF ON DEP PLAN WAS 133.8 CLB LIMIT BASED ON 25 DEGS C. CLOSEOUT CAME IN AT 133.9 BASED ON 109 PAX AND ZFW 112751 LBS. CURRENT WT WAS 134.4 AND CURRENT TEMP PER ATIS WAS 24 DEGS C SO I REQUESTED NEW TPS. RECEIVED NEW TPS AT XB01Z. NEW MTOW 134.1 AND TOOK OFF AT XB10Z WEIGHING ABOUT 133.9. CLBING OUT OF MMMX AT A LITTLE AFTER XB29Z RECEIVED RVSN 01 OF LOAD CLOSEOUT. NEW ZFW 113321 BASED ON 112 PAX. BY MY CALCULATION THIS PUT US AT 134.5 DURING OUR TKOF. TO MAKE SURE OF OUR ACTUAL TKOF WT I ASKED THE FLT ATTENDANTS FOR ACTUAL PAX COUNT. I HAD THEM COUNT TWICE AND CONFIRMED ACTUAL PAX COUNT AT 113. THIS EASILY PUT US OVERWT BY SEVERAL HUNDRED LBS FOR TKOF AT ONE OF OUR MORE CHALLENGING STATIONS. MY QUESTION IS; DO I NEED TO START HAVING THE FLT ATTENDANTS DO A HEAD COUNT PRIOR TO EACH TKOF? THE OBVIOUS POTENTIAL; IF WE HAD LOST AN ENG IN THIS SITUATION; WAS SOMETHING FRIGHTENING TO BOTH THE FO AND MYSELF. I AM CONCERNED THAT WE WERE GIVEN BAD DATA AT LEAST IN PART BECAUSE GND PERSONNEL ARE PUT UNDER MUCH PRESSURE TO GET FLTS CLOSED OUT AS QUICKLY AS POSSIBLE. BUT I BELIEVE THEY NEED TO KNOW HOW IMPORTANT THESE FINAL NUMBERS CAN BE AND SUPPORTED WHEN THEY TAKE A LITTLE EXTRA TIME TO MAKE SURE THEY ARE CORRECT ESPECIALLY AT THESE HIGH ALT OR SHORT RWY STATIONS.