I have an 83' El Camino w/ a 305, w/ a rochester quad carb. After screwing the air fuel mixture screws all the way in, how many turns out do you do to get an optimal setting? ThanX

A good generic setting is 2-2 1/4 turns, but that'll vary by elevation. The best way to set is with a vacuum guage. I can't remeber the exact procedure as I havn't done it yet on mine:mrgreen: . I'm still running the "2-2 1/4" setting :oops:

After I rebuild a CCC carb I preset the idle mixture screws at three turns off of their seat. After the engine is up to temperature and the ECM is in closed loop I use a scanner to monitor the dwell and do the final adjustment of both idle mixture screws (in equal increments) to get the dwell as close to 30* as possible. A vacuum leak or a bad oxygen sensor will make it impossible to set the dwell to 30*.

Here is a good article on how to do it:

http://tlentz.oldsgmail.com/howto.html#Mixture

:mrgreen: