AAD Aluminium Gen 3 Hemi Lifter Trays

The Fix for Factory Plastic Lifter Trays on High-RPM Gen 3 Hemi Builds

AAD Performance machines these billet aluminum lifter trays specifically for the Gen 3 Hemi to solve a known problem with the factory plastic trays: lifter rotation at high RPM. The stock plastic trays can allow lifters to spin under aggressive cam profiles, high-lift scenarios, or sustained high-RPM use, which accelerates wear and can lead to lifter failure. Part C021-0001-BK replaces them with a rigid, precision-machined aluminum alternative that locks the lifter in position and holds it there throughout the full RPM range. These are the correct version for factory Mopar lifters and Johnson Short and Standard Travel lifters that measure .728 to .729 inches between the flats. They are not compatible with MDS lifters or Johnson Hy-Lift lifters, which have different dimensional specifications.

Why Factory Plastic Trays Fail

The Gen 3 Hemi uses plastic lifter trays to hold the hydraulic roller lifters in paired sets and prevent rotation. At stock power levels with a factory cam, the plastic trays are adequate. When the engine is pushed harder, whether through aftermarket camshafts with higher lift and more duration, aggressive valvespring pressures, or sustained high-RPM operation, the plastic trays can flex, wear, or allow the lifter to walk in its bore. A rotating lifter will damage both the lifter and the camshaft lobe rapidly. The AAD billet aluminum tray eliminates that flex. The machined bore diameter is held to a precise tolerance that matches the factory Mopar and Johnson Short or Standard Travel lifter bodies, holding them firmly without binding.

Compatibility and Sizing

These trays are designed for lifters that measure .728 to .729 inches between the flats. This dimension covers factory Mopar non-MDS lifters and Johnson Short and Standard Travel lifters. Before ordering, measure your lifters. MDS lifters are not the same dimension as non-MDS lifters and will not seat correctly in these trays. Johnson Hy-Lift lifters measure .722 to .723 inches between the flats and require a separate AAD tray variant. Installing the wrong tray for your lifter style will produce incorrect fit and must not be used. Additionally, verify lifter travel clearance before starting the engine after installation. The lifter should not bottom out against the top of the tray bore during operation. The trays are designed to accommodate .400 inches or more of cam lift depending on the base circle dimensions of the camshaft.

Engine Applications

Vehicle Applications

Specifications

What's Included

• Pair of AAD Performance billet aluminum lifter trays (C021-0001-BK)
• Installation instructions

Frequently Asked Questions

The factory plastic trays hold the lifters adequately at stock power levels but can flex or allow lifter rotation under high-RPM operation, aggressive cam profiles, or high valvespring pressures. The AAD billet aluminum trays are machined to a precise bore diameter that eliminates flex and holds the lifter securely throughout the RPM range. For any performance build using an aftermarket camshaft or running the engine hard at sustained high RPM, the billet tray is the correct choice.

No. MDS lifters are dimensionally different from non-MDS lifters. This tray is designed for lifters measuring .728 to .729 inches between the flats. MDS lifters will not seat correctly in these trays. If your build uses MDS lifters, these parts are not appropriate and should not be ordered.

Use a digital caliper to measure the flat-to-flat dimension on your lifter body. Factory Mopar non-MDS lifters (including Hellcat lifters) and Johnson Short and Standard Travel lifters typically measure in the .728 to .729 inch range. Johnson Hy-Lift lifters measure .722 to .723 inches and require the separate AAD Hy-Lift tray variant. Always measure before ordering rather than assuming by brand or name alone.

The AAD billet trays are designed to accommodate .400 inches or more of lift at the camshaft, depending on the base circle diameter of the cam you are using. Higher base circle cams leave less available travel for the lifter before contact with the tray. Confirm your specific cam and base circle combination before building to avoid binding.

Yes, this step is required. With the engine assembled and the valvetrain installed, verify that the lifters do not bottom out against the top of the tray bore at maximum lifter travel. The lifter should not contact the top side of the tray during operation. Skipping this check and starting the engine without verifying clearance risks immediate valvetrain damage. This is a precision component intended for builders who understand Gen 3 Hemi valvetrain geometry.

AAD Performance sells these as racing parts with no implied engine warranty. They are appropriate for high-performance street builds, track builds, and race engines running aftermarket camshafts and non-MDS lifters. They are not appropriate for a stock 5.7L truck engine being reassembled with stock cam and reused stock parts. If you are not performing a performance build, these trays are not the right part for your application.

Yes. The Gen 3 Hemi lifter tray architecture is shared across the 5.7L, 6.1L, 6.4L, and 6.2L supercharged Hellcat and Demon engines. As long as the lifters you are using measure .728 to .729 inches between the flats, the AAD billet trays are compatible with the 6.2L platform.

AAD Performance states these are not available through standard distribution channels. Purchasing directly from AAD or through authorized specialty retailers is the correct sourcing path. Verify you are purchasing from a legitimate source, as billet precision components require accurate material and machining specifications to function correctly.

No. Johnson Hy-Lift lifters measure .722 to .723 inches between the flats, which is smaller than the .728 to .729 inch bore of this tray. The fit will be loose and the anti-rotation function will not work correctly. AAD Performance produces a separate tray variant specifically for Johnson Hy-Lift lifters. Order the correct version for your lifter specification.

Installation Overview

Installing these trays requires full engine disassembly to the point where the lifters and factory plastic trays are accessible. Remove the intake manifold, valley cover, and existing lifter trays per the factory service procedure. Seat the AAD billet trays in the correct orientation in the lifter bores of the block. Install the lifters into the tray bores, confirming the flat-to-flat orientation is correct for the lifter style. Before completing assembly, verify that lifter travel clearance is sufficient and the lifters do not bottom out in the tray at full travel. Complete the remainder of engine assembly per your camshaft and valvetrain manufacturer's instructions. This installation is intended for experienced engine builders. If you are not qualified to perform internal engine work on a Gen 3 Hemi, professional installation by an experienced engine shop is required.