You can use a vast aray of spring combinations to achieve the specs you are looking for, but keep in mind the main properties of valvespings in a head
- Seat Pressure at installed Height
- Coilbind
- Seat Pressure at Lift
- Valve Spring Weight
- Harmonics
- Wear
By changing springs you can charge any of these factors in a positive or negative way. In VTEC engines progressive springs are great for longevity and the wear characteristics, due to the softer spring rate while under non-vtec conditions. This is why the Type-R Springs are great for Street application.