Hey there, if you're dealing with those problematic AFM lifters on your Chevy or GM truck with a 4.8L, 5.3L, 6.0L, or 6.2L LS engine, these Mizumo lifter guides are exactly what you need. This kit comes complete with 2 front AFM lifter trays with bolts and 2 rear AFM lifter trays with bolts - everything required to replace those worn-out OEM parts. The quality is seriously impressive, manufactured under strict ISO 9001:2000 standards to ensure they meet or exceed original equipment specifications. What's great is they use advanced materials and design technology to provide quiet, maintenance-free operation that'll make your engine run smoothly again. Installation is straightforward if you're comfortable with engine work, and they're guaranteed to fit perfectly. These aren't some cheap knock-offs - they're built to last with durability that'll stand up to daily driving demands. Whether you're fixing existing lifter issues or doing preventative maintenance during an engine rebuild, these guides deliver reliable performance that'll have your engine running like new. The improved design actually provides noticeable enhancements to engine operation, reducing noise and increasing longevity. It's one of those repair parts that actually makes a difference you can feel and hear.