Check the listing for details. KPMI Racing Valve Spring Kit Kibblewhite 30-30720 For 2004-2005 Honda TRX450R. Condition: New. Listed at 139.99 USD. Since 1939, KPMI® has taken great pride in our ability to design innovative performance improvements for valvetrains. This innovative ability has never been more apparent than with the development of the high tech lightweight racing valve spring kits for the incredibly stressed and torturous environment in today's high revving 4-stroke engines. The challenge to engineer a valvetrain that would outperform OEM systems, that in some cases included titanium components, was not an easy one. This task would require the concentrated efforts of every member of KPMI®'s design team. It was apparent early on that an OEM style spring with a bit more pressure was not going to be the complete answer for these engines. Working together as a team enabled KPMI® to evolve with a "unified system" approach. In fact, these innovative high performance lightweight valve spring kits, would not only outperform factory parts, but outlive them as well. Each KPMI® spring kit is designed for its specific application, taking into account several critical parameters including; cam profiles, harmonics, natural frequency of the springs, valvetrain mass, required pressure, wire stress, fatigue life, and engine rpm, just to name a few! Today KPMI® proudly offers complete high performance lightweight valve spring kits for a host of applications. TypeIntake/ Exhaust Retainer MaterialTitanium Intake Valve Lift0.440" Intake Installed Height1.215" Intake Seat Pressure40# Intake Open Pressure147# Intake @ Lift0.440" Exhaust Valve Lift0.440" Exhaust Installed Height1.365" Exhaust Seat Pressure70# Exhaust Open Pressure203# Exhaust @ Lift0.440" NoteThe Exhaust springs for this kit include a progressively wound Inner Spring, which should be installed with the tightly wound end seated on the HT Steel Basewashers.