quadrajet idle mixture screws all the way in

[chris71]

hey guys,
I have a bone stock 71 qaudrajet on a bone stock 40,000 original mileage 350. had the carb rebuilt about a year ago and I just getting the engine back together because I had the cylinder heads redone (hardened seats, one peice valves). still has the the original points style dist, the PO did the new cap, points, condenser routine. well i got her together and she is idling ok, a little rough but not bad (seems like she has a cam when she doesnt) but the main problem is a hesitation/sputter under part throttle, WOT she seems good, at highway cruise she seems fine, so i went to adjust the idle mixture screws, and did the turn in 1/2 turn until highest vacuum, but i was able to turn the screws all the way in with no change in vacuum and she will still idle okay. the timing is at 8* and the vacuum is 15, i havent got a chance to check the dwell yet, because i cant find my meter. I know a new brass float was installed, along with the rebuild. does anyone know what may be going on here?


P.S. please no qaudrajet bashing or go buy a holley/edlebrock talk, i want to keep this engine/carb/dist. setup all original and numbers matching like it is. thanks in advance for your help.