I have a MSD streetfire distributer and i want to add a rev limiter to it. on jegs they have the MSD Extreme Output HEI Module but it says that its for a 4 pin connecter...but when i look in the instructions on msds website it says that the 4th pin is for the tach and to use the tach output on the distributer if the one from the control module is inaccurate....can someone clarify this mess for me...i really just want a rev limiter...

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