I have been getting more frustrated with the performance of my engine. I cant seem to get it to idle properly and that it chugs consistently now at about 70 mph, like its in a vapor lock. One day its totally fine then the next it runs like, well I will say crap. I am at a point of either replacing the carburetor again, or going to fuel injection system. 389 with a 4 barrel Edelbrock carb. I have rebuilt the carb once already, I have cable linkage as well and that seems to be staying in a high idle as well. When I drive and get home it seems to be idling fast in park, if I put my toe under the pedal and drop it the idle will then drop. Just little things that are making the car run inconsistently. BTW I do live in the state of California , so gas may be playing a part in this as well? I have played with jets on the carb and the idle adjustment but it just seems the carburetor is so inconsistent, fuel additives don't seem to do squat. Electronic fuel pump?