Knowing that the original Bosch HKZ unit in the early 911S was essentially introduced to eliminate 'plug fouling', can some kind soul please explain in simple terms to a (completely inept) layman the key 'evolutionary' differences between the 3-pin, 6-pin and 8-pin Bosch HKZ CDI units and what performance or other gains each configuration brought to our 6 cylinder oily bits?

Thx

Martin