Exactly, a directional tuning aid then it is what it is BUT, without one you never REALLY know where you're at and they are eye opening when tuning the 4 circuits on the street........idle, transition, cruise and WFO............ thumbs

72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....