[LH Lead-Foot]

It will work without damage to ignition module, but is not common practice. Controlling B+ to the HEI is best practices. Note; If you measure the current to the HEI coil, you will find it is pretty high as the coils primary is 1.2 ohms. Use a toggle switch and a relay to handle that current. Note the resistance of high voltage coils sold by speed shops. The lower the resistance, the higher the current, but higher the output voltage.

MATH; 14 volt DC divided by 1.2 ohms = 11.6 amps. (E over I X R) Ohms solving circle.

Old trick, Anti-Theft using starter;
If equipped with cruise control, the set switch goes to ground on many GM vehicle produced before 1986. Fused B+ to relay to handle 20 amps or more, can be energized by "Set" button on coil side of relay. Ignition switch purple wire goes to started for crank, so interrupted by relay contacts.

Operation; Key in right hand, while left hand finger on set button and held on during cranking, will complete circuit to starter's solenoid. Turn key to crank normally, release cruise set switch, cruise operates normally while driving.

Important; check your cruise control's set switch for normal operation with key on and some and newer vehicle provide B+ signal instead.