I have a 69 Jaguar XK-E, and it used to be an owner would approach me and ask if I wanted to buy his car, also an E. At that time, either one of two things had been done to the car, took off the Stromberg carbs and/or put on Petronix. I always passed on the offer. However, about two years ago, I had a string of bad experiences with my E’s ignition system, and normally this car is surprisingly reliable. A rotor with a pin hole in it was the culprit one time, bad condensor another time. It became apparent the the quality control on point ignition was not there. My shop professional strongly suggested Pertronix and at first I strongly resisted. He made me a deal whereby if the Pertronix wasn’t all he said it would be, he’d put the ignition back to the original. OK, so I did the Petronix and also the coil, having read that the older coils did not play nicely with the new stuff in the distributor. Well, truth be told, the Pertronix system has worked perfectly for over 3 years. I was so impressed that I put one in my 47 Chris Craft with its Hercules engine and Autolite distributor. Made a major difference there as well.