What do you mean "modern" ignition? Are you talking Mopar electronic ignition or something like MSD? With the Mopar electronic ignition it should not be an issue and hook up normally, however if you are using a MSD or other CDI ignition, you will need their adapter. MSD has 2 different adapters, you need to call them to find out which one you need, I did the opposite and bought the one I was sure would work, it didn't and I called MSD and they told me I needed the other one which worked fine.