Fits Cummins 5.9L L6 24V DIESEL Black Lightening. Includes Intake & Exhaust Valves, Keepers, Springs, Retainers, Stem Seals. Components are Matched for the Best Compatibility and Performance. Black Lightning racing valves are forged from premium 21-4N stainless steel. They have undercut stems and swirl-polished heads to help the flow of both fuel and exhaust gases going into and exiting the combustion chamber. The valve heads are also designed with thinner margins to reduce weight and inertia. Black Lightning valves also feature a unique nitride coating which is better than chrome for higher revving race engines producing less friction, exceptional wear resistance, and increased strength and ductility. From stem to head these race quality valves are engineered to perform in the most demanding pro race engine environments The Springs, Retainers, and Keepers are designed to function together to give you maximum performance. Metal Clad High Performance Valve Stem Seals. Includes 8 Intake & 8 Exhaust Street Performance Stainless Steel Valves, 16 HP Valve Stem Seals, 16 HP Springs, 16 HP Retainers, & 32 HP Keepers. THIS KIT COMES WITH THE FOLLOWING PARTS. (12) BLACK LIGHTNING PERFORMANCE INTAKE VALVES. (12) BLACK LIGHTENING PERFORMANCE EXHAUST VALVES. (24) HIGH PERFORMANCE SPRINGS. Shape=Single w/ Damper, Coil Bind 0.866. HP VALVE STEM SEALS. Nominal Stem Dia 0.276. HP KEEPERS – HEAT TREATED. Chrome Molly, Stem Diameter. 275, 7 Degree, OD 1.065″, Step 1 Diameter 0.706″, Step 2 Diameter 0.570. This is a High Performance Valve Train Kit. This kit is provided by Qualfast. You are solely responsible for determining the suitability of any and all items. APO/FPO/PO BOXES Deliveries excluded. Please specify sizes when ordering, even if they are Standard Sizes. Your order will be held for 24 hours, awaiting your response. Usually we will find a way to help you out. Any limitation contained herein does not apply where prohibited by law. Any suits arising from the sale of the goods described in this add, must be filed in Clackamas County, Oregon and such suits shall be governed by the laws of Oregon. Grumpys Performance Center is a One-Stop Service and Dealership Alternative. We have been rebuilding quality engines for over 40 years. We pride ourselves on the continuous quality of our workmanship. We employ state-of-the-art equipment in our new 40,000 square-foot machine shop and warehouse located in Oregon. We are both ASA and Engine Pro certified and a longtime member of the Automotive Engine Rebuilders Association. Thats WHY We are the #1 Diesel and Gas Engine Remanufacturing Machine Shop in the Northwest and we are now happy to be expanding our services NATION WIDE. We have full time customer service representatives available to process your orders. Monday through Friday, excluding holidays. PERFORMANCE is our middle name!