Forgive my ignorance but I dont know what a dial back timing light is. This is the basic timing light that you hook up and push the button and it flickers. when revving past 2500 the light barely flickers at all. The truck wont rev past 5500 without struggling and it barely pulls to that. Whenever the engine was first put in it would peel out at part throttle and only reving to 2000...now it stumbles below 1500 and just doesnt pull through the rpms. The only thing that hasnt been replaced is the distributor or the MSD box. Thanks for the time and help