ignition system ?????

A stock GM HEI module when mated to a stock style coil actually has less rpm potential

Sure, but…so what? The stock (Mopar) style coil is not the correct one to use with HEI. Whatever ignition system you pick, its components have to be matched to one another.

No need to guess or assume here; go read the HEI article I linked; there are oscilloscope traces comparing Mopar electronic to HEI on the same engine. Note the higher voltage and longer spark duration with HEI.