which coil?

[Sinitro]

Coils can be oil-filled or epoxy-filled. Oil-filled coils are recommended to be mounted vertically because they can leak; with epoxy-filled coils, you don't have that issue. For that reason, I initially bought a Pertronix Flamethrower III coil (oil-filled) and because I didn't want to re-think how to mount it vertically, I returned it and replaced it with a Pertronix Flamethrower II that's epoxy-filled. Those are more expensive...go figure.

Note that mounting an oil-filled coil vertically, is for its internal oil to better circulate around the coil's internal windings for cooling purposes...
As a coil heats up its efficiency is affected and its voltage/current/output can/will decrease..

Just my $0.02...

 

[Geoff 2]

Talking about inductive ign.
Nope, a spark with higher current [ such as using a coil with lower turns ratio ] produces a shorter duration spark.....not longer duration. However, this is not a problem with inductive ign systems because the spark already has long duration, about 10 times the duration of a CD ign spark.

 

[HALIFAXHOPS]

Few ways to look at Voltage. Remember most stock coils were 28KV even on the Hemi cars.

 

[HALIFAXHOPS]

Big one is the plugs resistance really.