Don,
I too have wondered about this use of distributors among the Buick guys.
I know you use the TEC3... and there can be no argument that a 60-tooth crank trigger will give more accurate timing than a 3-magnet one.
The E-motive TEC3 has ignition circuits built - in that hits the coils on the DFU (Which contains 3 standard GM DIS Coils) with energy comparable to CD systems such as MSD. That's the difference. This is probably more than enough to make up for any energy lost by firing two coils at once.
On my Stage II (yes, I
will shock the world when my project finally gets off the ground) I will be using the TEC3r to fire 6 coils in a non - waste spark configuration - but only because it's an odd - fire motor
, using the GN cam sensor for a reference signal. I'm not very concerned about the accuracy of the cam sensor since the cam reference has a very wide tolerance. You could do 6 coils too with the TEC3 if there is a desire for even more energy to the plugs.