I have had Koni SPA 1s on my Dart for years I also have the monoleaf/CalTrac setup. I purchased a pair of the Calvert 90/10s last year and put them on. I haven`t pin pointed the problem but I believe the front was rising to fast as I was spinning the tires a lot more than normal. I put the Konis back on and the problem went away. I have heard the Calverts work good but they just didn`t on my application.