I have a 85 z28 with a 350 has flowtech headers. And edelbrock performer. Intake and a crower 268 duration 450 lift @0 degrees of timing just a little cam but I put this street avenger 670 holly on there and its seems likes it is to rich haven't put a light on the timing but did advance it till hard cranking and then backed it off alitttle. Not sure but my buddy messed with it a little and now it seems like the choke is always on loads up at idle if u know anyone who knows these carbs let me know looking to get this done asap thank john