Engine & Power · Buyer's Guide

Valve Springs & Lifters

Valve springs control how fast your engine's valves close after the camshaft opens them. Lifters are the components that ride on the camshaft lobes and transfer that motion to the pushrods. If you're installing an aftermarket camshaft, you MUST upgrade both — stock springs can't handle aggressive cam profiles (causing dangerous 'valve float'), and MDS lifters are incompatible with aftermarket cams. This is not optional — it's the difference between a working engine and a destroyed one.

Recommended Picks

A starting point for your build, sorted by budget.

Best ValueMost affordable in this category
Comp Cams Non-MDS Hydraulic Roller Lifter Set (HEMI)

Comp Cams

Non-MDS Hydraulic Roller Lifter Set (HEMI)

$380
Mid-Range PickBalanced price and performance
Mopar Non-MDS Lifter Set (HEMI)

Mopar

Non-MDS Lifter Set (HEMI)

$420
Premium PickTop-tier brand and performance
Comp Cams .600" Lift Beehive Valve Spring Kit (HEMI)

Comp Cams

.600" Lift Beehive Valve Spring Kit (HEMI)

$450

All Valve Springs & Lifters (3)

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4. CAMSHAFT UPGRADES

What the Cam Does

The camshaft controls when and how far the intake/exhaust valves open. An aftermarket cam with more lift and duration lets the engine breathe better at higher RPM, fundamentally changing the power band and sound.

Cam Stages

Stage Profile Idle HP Gain (6.4L) Street Use
Stage 1 Mild (e.g., BTR 220/228) Smooth +30–50 HP Daily driveable
Stage 2 Moderate (lopey) Noticeable lope +50–70 HP Street/weekend
Stage 3 Aggressive Rough/cammy idle +70–100 HP Mostly performance
Stage 4 Race Very rough +100–120+ HP Track only

Required Supporting Parts (The Master Kit)

Every cam swap on an MDS-equipped engine REQUIRES:

  1. Non-MDS Lifters — MDS lifters will fail with an aftermarket cam profile
  2. Valve Springs + Retainers — Stock springs can't handle increased lift
  3. Pushrods (intake + exhaust) — Correct length for new lift specs
  4. VVT Limiter/Lockout — Control Variable Valve Timing with the new cam
  5. MDS Delete Plugs (qty 4) — Seal oil passages from removed MDS system
  6. Custom ECU Tune — Mandatory for idle, fuel, timing tables

MDS Exception

Manual transmission Challengers (Tremec TR-6060) do NOT have MDS. Skip: MDS lifters and MDS delete plugs. Same for 6.1L SRT8.

Key Brands

  • BTR (Brian Tooley Racing): Stage 1–4 cams purpose-built for Gen III HEMI. Very popular in the community. BTR Stage 1 = 220/228 .590/.580 113.5 LSA.
  • Comp Cams: HRT (Hemi Racing Technology) line. Widely available, good support.
  • Texas Speed (TSP): Known for aggressive stages. Complete kits available.
  • 797 Performance: Complete cam kits for 6.4L with everything included — plug-and-play minus the tune.

Sound Impact

A camshaft is arguably the biggest single change to how the car sounds at idle. A Stage 2+ cam gives the classic "potato-potato" HEMI lope that enthusiasts love.

Site UX Recommendations

  • Error-level warning when cam added to build: "A camshaft swap requires a complete master kit. These are the required supporting parts..."
  • Cam builds should auto-add a "You need a tune" warning.
  • Checklist UI for master kit components when cam is selected.
  • Stage filter (1/2/3/4) on cam listings.

11. ENGINE INTERNALS (STAGE 3+)

When Internals Are Needed

  • Naturally aspirated builds pushing past ~500 HP.
  • Forced induction builds pushing past ~600–700 HP.
  • Aggressive cam + headers + intake combo on the 5.7L.

Key Parts

  • Forged Pistons: Replace stock cast pistons for boost/nitrous tolerance. Mahle, JE Pistons.
  • Forged Rods: Replace stock rods for high-RPM/high-boost durability. Manley, Eagle.
  • Head Gaskets: MLS (Multi-Layer Steel) head gaskets required for boost. Cometic.
  • ARP Head Studs: Replace head bolts with studs for improved clamping force under boost.