Hydraulic lifters go quiet or noisy depending on how consistently they bleed down, and oil aeration is what wrecks that consistency. These use a self-contained hydraulic cartridge with less oil volume inside it, so bleed rates stay matched across all sixteen. The cartridge is also serviceable, which means a set can be rebuilt on a bench instead of replaced.

COMP Cams 89571-16 Evolution Retro-Fit Hydraulic Roller Lifter Features:

• Fits GM LS, LSX and Warhawk engine blocks.
• 0.842 in. lifter outside diameter with a 2.660 in. lifter seat height.
• Patented Hydraulic Cartridge Technology for consistent bleed rates between lifters.
• Reduced internal oil volume is less affected by oil aeration.
• Thick wall body resists distortion, keeping hydraulic performance consistent.
• Precision controlled bleed down rate holds up at high rpm and quiets startup noise.
• Retro-fit link bar design with two oiling features.
• Hydraulic element is serviceable, so the lifters can be rebuilt.
• Tall body fits both standard and tall lifter bore blocks; sold as a set of 16.