Slant 6 wont idle after warm

I used the Pertronix, it was very easy to install. I don't know if I was lucky but I didn't have to adjust the timing. I bought the car used, 1969 Dart convertible. I believe the ignition parts were pretty worn when I bought the car and became considerably worse the few times I drove the car. The slant six make decent power and is very fun to drive now. I have a engine swap planned but I am not in a rush now. Thanks again for all of the input, this site is great!