5.0L Tech
On a rebuild 87 motor in an 92 body. It is still a Speed Den Set up.
On idle, the engine modulates between 700 and 1000 rpm, the Tack just bounces up and down rrrrv....rrrv...rrrv... ( I hope you get the picture). When I accelerate, the "wobble" in the tack is quicker and maybe only 200 rpm...