Barry50

Hi Steve Educate an oldie, but what is a dizzy?

I have renewed the twin SU`s and fitted K&N filters and changed from points to electronic ignition, took the car in to be tuned and was told that the timing chain was very noisy, my spitty now runs but tends to miss fire and holds back, this has only happed since installing the electronic ignition, can anyone advise. (the HT coil is 12volt) Cheers Barry50.