If your engine is starting to make a loud knocking or tapping sound, then it's time to immediately check your engine for signs of wear and damage from faulty components. If even just one of your lifters is collapsed you need to replace both of them at the same time to ensure even wear patterns, and luckily for you, these Drag Specialties Front and Rear Lifter Blocks are just what you need! Precision-made from high-quality materials, these blocks are designed to OE spec to ensure quick and easy repairs and a stock look.