I am wondering if i'll run into any problems without using a tach adapter, the Autogauge PN is 2300, its a black 3 3/4" tach. I have an MSD 6a and am wondering if it will work with the tach with no tach adapter. The tach directions say to just plug right into the tach terminal on the MSD 6 series. Anybody have this combo? and does it work w/o tach adapter?