Wally/Montana,
If your system is 12 volt and you don't have a HEI...OR a internally resisted coil..OR a existing resistance wire in the harness, then you would need a ballast resistor wired as you have indicated above when the key is in RUN.
If all of the above is true, don't forget that the wiring should have allowances to bypass this ballast resistor when the key is turned to START.
Stuart
