Quadrajet tune??

[Huck]

See the red truck under my ID? It is almost pure stock original--some of the best options like--350V8, turbo 350 trans, Posi rear, HD springs, front sway bar, factory AM/fm, Tint glass, Air, --
--I put in a super nice Tach Dash, HEI and a real nice Van tilt----------new carpeting, seat cover and then did a complete rebuild of the bed with rust free sides, good floor, new tailgate, cab corners, rockers, etc.

I am about ready to put it up for sale but have a couple of issues to address--
1- need to get the 350 rear main seal replaced
2- it runs too rich---to the point it stinks and activates the alarm in the garage---not just when idling cold but also when warm.

Is there anything I can do to the carb while mounted to get it to run leaner? I know about the idle screws that you can turn but that is "idle" only adjustment. Do i need to pull the sucker and get it rebuilt? It does run like new in every other respect.