1986 JOhnson 70 HP Thermostat spring clarification

[tewart]

I installed the new water pump kit 0432955 which has the thermostat parts included. I pulled the thermostat cover and have a straight 5/8" diameter spring. The instructions state, "If you have another style thermostat spring, discard the original spring and thermostat cover. Replace them with the conical shape spring and cover. I do not have the 15/16" ID spring straight spring. Do I use my old spring and cover or replace it with the new cover and conical shaped spring?