This is what the 75\' eldo carb looked like *before* I rebuilt it...What a mess!! *IF* I understand this correctly, there will be no need to do a jet changing. Changes can be made using a F/A meter, and simply backing out the screw on the Aneroid for richer mixture, and screw it in for leaner mixture. ...that is *IF* I understand this correctly ;-) (See pic #6) There is a good explaination and diagrams of the Aneroid and it\'s operation on p. 10, 26 & 27 of the Q-Jet service manual which can be found in a 7.5mg pfd file at this URL: http://bdub.net/manuals/Quadrajet_Service_Manual_1981.pdf