Turn signal rate 71 Cutlass

The turn signals blink real slow on my 71 Cutlass. I have new battery and flasher installed but no change. What regulates the frequency of blinking of the turn signals?

Actually what controls flash rate is the resistance of the wiring and bulbs that the current is going through. If you wanted to try it you could try an electronic flasher that might regulate it better for you. Sounds to me like you have a bad flasher.