I know this is a dumb question as I have been running a Duraspark II ignition in my 89 coupe 4cyl to v-8 conversion love affair so I know it works to get me into the 13's, but am I losing anything by using the stock 4 banger cdi coil with the duraspark box? I am going to all MSD in the future, but I am curious as to why they make coils marketed for efi/cdi and the old Duraspark ignitions.