LED tail light

ok I know many of you are using LED bulbs in the tail light ...

1. does it blink like a old bulb ( staying lit as well as blinking )
2. Red or white LED bulb
3. what style LED bulb looks more like an old bulb ( no hot spot )
4.will i have to change the flasher if im only doing the back lights ?
70 Dart here ...

Thanks All