Thats what I was worrying about. It is going to be for a 1970 SS with about 550 HP and a tremec TKO-600. I like the idea of factory appearance but I also like the idea of having a more precise gauge.Something to be aware of is the fact that some tachs can lag quite a bit behind the actual acceleration rate of the engine. You could actually be shifting a few hundred rpm higher than you think. They could still be accurate at any steady cruise rpm.