The Industrial Injection Duramax 130lb. Performance Valve Spring Kits were designed with performance in mind. We recommend this valve spring kit for engines that are pushing over 45psi boost and/or 3200rpm. This performance valve spring kit will help prevent valve float, there for allowing your truck to run more efficiently and make more power safely. This comes as a complete kit with conical valve springs, billet steel retainers, chromoly spring seats and valve locks to provide the best durability and reliability to your valve train.