Not a fan of the majority of aftermarket electronic distributors when a know proven quality Bosch electronic distributor is easily available. This distributor can be recurved as needed. Do know most of the distributor mechanical advance is in by 3500 rpm, above 4,000 rpm is is mostly a non-issue.
Keep in mind the large diameter of the magnetic trigger unit's arms in the stock Bosch distributor when compared to the majority of aftermarket offerings. The larger diameter has less trigger angle error due to the larger diameter. When the trigger diameter is reduced, much greater precision is required to equal what is so easy to achieve with a larger diameter triggering device. Add to this the high quality and durable mechanical parts used in the stock Bosch distributor, where the vast majority of aftermarket offerings are usually very questionable for quality of materials, durability and reliability.
This Bosch distributor with the MSD 6 ignition unit and stock Bosch coil has been the staple of every exxe owned for decades. All have been totally reliable with zero problems over the decades. The problem waiting to happen is the stock Bosch rotor with resistor built in. The MSD 6 will fast roast that resistor in short time causing an ignition failure. Either a non resistor Bosch rotor can be used or bypass the resistor with copper tape and solder.
As for failing MSD boxes, we used them in the Mazda rotary powered LeMons racer, both Triumph cars, the 74' exxe and where possible. None have had any problems what so ever. All previous points based ignition cars run and start MUCH better with the MSD and proper coil and spiral wound ignition wires.
Bernice