850 With Marelli S118 Distributor / With Marelli S124B Distributor 1969, Ignitor II Adaptive Dwell Ignition Control (9MR-LS3) by PerTronix. The has many of the same great features that the Ignitor has, but it's smarter. units sense the coil current level and use a powerful micro controller to adjust the dwell. Variable dwell helps to maintain peak energy throughout the entire RPM range. systems develop up to 4 times more energy between 3000 and 5000 RPM than standard ignition systems. High RPM performance is improved when used with the Flame-Thrower II super low resistance (0.6 ohms) 45,000 volt coils. If you appreciate value, nothing else comes close to this superb PerTronix product. Backed by a high level of performance, it leaves behind all its competitors.