Gen lll hemi install in a 67 barracuda

I used Hotwire. No you do not the ECM that came from the car. Their customer service is top notch. I went with digital gauges and they were excellent in helping hook up my tach.
Modern Muscle Extreme was very helpful when they weren’t as big in the Hemi stuff as they are now. In the beginning you could talk to Dave Weber directly. Now not so much they have gotten big into high horse power GenIII stuff. Like said above you can use any small block trans. Even a Toyota Supra has been done.