ANSWER: The 25042X point set has a higher tension spring arm for better stability at higher RPMs. The downside of this is that the higher tension can increase point cam wear on the distributor. If you have an application that spends most of its time below 5,500 RPM, stick with the standard point set. Secondly, it is still best to switch to electronic ignition which offers more accuracy, better secondary ignition voltage output, and nothing to adjust. If your application allows you to utilize electronic ignition, it is worth the cost of upgrading.