If the shoes ever start dragging due to weak springs it will cause excessive heat within your clutch bell and the springs wll definitely go weaker to the point to where they won't hold the shoes down even at low rpm's. It should be very difficult to pry your clutch shoes open by hand. If you can open them easily...even just a little bit by hand it doesn't take much for them open to the point of dragging inside the clutch bell. Clutch shoes can still be in good shape for the moment but they will start wearing fast now if the springs have softened. Try MUGEN 1.0 or 1.1 springs. They are very strong and may be of much better quality than what came stock with your car. They will definitely let the engine build better revs for better low end GRUNT.