Gas Mileage???

Lack of vacuum advance. It's ping is probably related to a fuel curve issue. Getting control of the advance curve for a street car is also different than a race car or car with a high stall converter. All in at 2500 is not a good thing with a tight converter and slightly lean mixture. Slow the mechanical advance curve and or shorten it and make sure total timing with vacuum in not going over 45 degrees. You may need stiffer metering rod springs and or smaller rods too.