Here is my take for a rev limiter for HEI ignitions. HEI ignitions typically do not require ballast resistors because coil current is safely limited by the HEI circuit. Most rev limiters hook to the coil (-) and by grounding keep the ignition from firing, since spark happens when the coil current is interrupted. Since the coil current is no longer HEI controlled, it will greatly exceed coil specifications when rev limiting.
An example is 0.5 Ohm e-core coil with a normal peak current of less than 6 A, may peak to 28A when the rev limiter is operating. The high current may cause the coil to fail, or the greater than normal ignition voltage ( when stepping out of limit) may damage a HEI unit.
If the rev limiter does not have a current limit, a standard two terminal ballast resistor could be placed in series with rev limiter connection to the coil (-).
Integrated rev control ignitions may incorporate current limit, and better controls retard timing, for rev or traction control.