Introduction

The AMC AMX is a classic American muscle car, and its 390 or 401ci V8 engine benefits greatly from a performance camshaft upgrade. The Edelbrock Performer RPM cam (part number 2102 or 2103) is a popular choice for street-driven AMXs, delivering a noticeable power increase across the mid- and upper-RPM range while maintaining decent idle quality. This guide provides a comprehensive, step-by-step walkthrough for installing this cam in your AMX. We’ll cover everything from preparation and teardown to careful installation with timing chain alignment, then reassembly and initial startup. Following these instructions precisely will help you extract the maximum performance from your engine without encountering common pitfalls.

Tools and Materials Needed

Gather all required items before starting. Having the correct tools on hand prevents interruptions and ensures a smooth job.

  • Socket and ratchet set: 3/8″ and 1/2″ drive, including deep sockets up to 19mm and 13/16″ for spark plugs (if removal is needed).
  • Torque wrench: 1/2″ drive capable of 0–150 ft-lb for head bolts and main caps.
  • Camshaft installation tool: A plastic or aluminum pilot tool protects cam bearings during insertion.
  • Timing chain cover gasket set: Fel-Pro TCS 45612 or equivalent.
  • Intake manifold gasket: Edelbrock 7201 or Fel-Pro 1250 compatible with AMC heads.
  • Valve cover gaskets: High-quality rubber or cork – avoid cheap paper sets.
  • Assembly lube: High-zinc camshaft break-in lube (e.g., Comp Cams 159 or Joe Gibbs BR30).
  • Engine oil and filter: 10W-30 or 10W-40 conventional oil with high zinc/phosphorus (or a break-in additive).
  • Timing chain and gears (optional but recommended): Edelbrock 7812 or Cloyes double-roller set for AMC.
  • Clean rags, nitrile gloves, safety glasses.
  • Shop manual for your AMX: Factory or Haynes manual with torque specs.

Pro tip: Label all removed fasteners and components to avoid confusion during reassembly. Use plastic bags and a marker.

Preparation and Safety

Park the AMX on a level concrete floor. Disconnect the negative battery cable to prevent accidental starter engagement. Drain the engine oil and remove the oil filter. If the engine has been run recently, allow it to cool completely before removing components. Clean the engine exterior around the intake manifold and timing cover to reduce contamination.

Disassembly Sequence

  1. Remove the distributor – note rotor position and mark the distributor housing orientation relative to the intake manifold. Label plug wires.
  2. Remove the intake manifold after unbolting the carburetor, fuel lines, vacuum lines, and throttle linkage. Use a gasket scraper to clean the manifold surface.
  3. Remove both valve covers and then the rocker arms. Keep each rocker and pushrod in order for reinstallation in the same location.
  4. Remove the cylinder heads – loosen head bolts in a crisscross pattern, lift heads off, and place on a clean bench. Remove head gaskets.
  5. Remove the timing chain cover – drain the cooling system if necessary (some coolant passages require draining). Unbolt the cover and gently pry it off.
  6. Remove the timing chain and gears – unbolt the cam gear, crank gear, and slide the chain off. Note the alignment marks for later.

Camshaft Removal

With the timing chain and gears off, you can remove the old camshaft. The cam rides in bearings pressed into the block. Carefully slide the cam out through the front of the engine. If the cam is stuck, rotate it slightly while pulling. Do not force it – you may damage the bearings. Once removed, inspect the cam bearing surfaces for scoring or wear. If the old cam is wiped on any lobe, you may need to replace the cam bearings (a job best left to a machine shop).

Clean the cam journal bores with a lint-free cloth and brake cleaner. Look for any debris that could contaminate new bearings. Apply a thin coat of assembly lube to each journal.

Installing the Edelbrock Performer RPM Cam

The new camshaft must be treated carefully to avoid damage to the lobes and journals.

Lubrication

Generously apply high-zinc assembly lube to all cam lobes, distributor gear, and thrust plate. Also coat the cam journals. Do not use engine oil alone; dedicated break-in lube provides necessary protection during the first few minutes of run time.

Camshaft Insertion

Slide the cam into the block using a pilot tool if available. Turn it slowly to engage the bearings. Once fully seated, check end-play using a feeler gauge between the cam gear mounting face and the block thrust surface. Spec is 0.001–0.007 in; if too tight, you may need a thinner spacer or machine work.

Timing Chain and Gear Installation

Install the timing chain set with the correct alignment marks. For AMC engines with the Edelbrock cam, the typical “dot to dot” timing places the crank sprocket keyway at 12 o’clock and the cam sprocket “0” at 6 o’clock. Refer to the cam card for exact indexing. It is highly recommended to degree the cam to verify the intake centerline. This requires a degree wheel and dial indicator but ensures optimal performance. If you are not comfortable degreeing, have the engine shop do it. A mistake of one tooth can ruin idle and power.

Timing Cover Installation

Apply a thin bead of RTV silicone at the block/pan junction, then install the timing cover with a new gasket. Torque the cover bolts in sequence to 7–10 ft-lb. Do not overtighten – the cast aluminum cover can crack. Install a new front crankshaft seal and oil slinger if equipped.

Reassembly

Now reassemble the top end with care.

Cylinder Heads

Clean the head and block surfaces. Install new head gaskets (Fel-Pro 8553PT or equivalent) oriented correctly. Place each head onto the block, then install head bolts with threads lightly oiled. Torque in three steps per the factory spec (typically 110–120 ft-lb for iron heads).

Rocker Arms and Pushrods

Oil each pushrod ball and place them in the original order. Install rocker arms with new nuts. Adjust valve lash according to the cam card. For a hydraulic cam, tighten the rocker nut to zero lash (pushrod just stops spinning freely) plus ½ turn. For a mechanical flat-tappet cam, set lash hot as specified (e.g., 0.022 in intake, 0.024 in exhaust).

Intake Manifold

Apply a small amount of RTV at the four corners of the intake gaskets (where they meet the block/head). Install the manifold with new gaskets and torque in a crisscross pattern to 30 ft-lb. Reattach the carburetor, fuel lines, vacuum lines, and throttle cable.

Final Steps and Initial Startup

Oil and Filter

Install a new oil filter (Wix 51515 or equivalent). Fill the crankcase with break-in oil or conventional 10W-30 with a bottle of ZDDP additive. Do not use synthetic oil until after the cam is broken in.

Priming the Oil System

Before cranking the engine, prime the oil pump using a drill and priming tool (available for AMC distributors). Spin it until oil flows from all rocker arms and the pressure gauge shows 30+ psi. This coats the new cam lobes immediately.

First Start Procedure

Reconnect the battery and fill the cooling system. Start the engine and immediately raise the RPM to 2000–2500 and hold it steady for 15–20 minutes. This is the critical cam break-in period. Do not let it idle – low oil pressure and minimal splash can cause lobe wear or failure. After break-in, check for leaks, unusual noises, and reset valve lash if needed (many cams require a re-torque after initial run).

Performance Tuning

To maximize the Edelbrock Performer RPM cam, you will likely need to adjust the carburetor and ignition timing. Start with initial timing around 12–14° BTDC, total timing around 34–36° by 3000 RPM. Re-jet the carburetor richer by 2–4 sizes on both primary and secondary circuits if using a stock Q-Jet or Edelbrock carb. A performance ignition system (HEI upgrade or MSD) is beneficial. Expect a rough idle with vacuum around 12–14 inHg; adjust idle mixture screws for best vacuum.

Conclusion

Installing an Edelbrock Performer RPM cam in your AMC AMX is a rewarding project that can transform your car’s power characteristics, especially with supporting modifications like headers and a higher-stall torque converter. Follow the steps precisely, use high-quality parts and lubricants, and take your time on the timing chain alignment. If you are uncertain about degreeing the cam or valve adjustment, consult a trusted engine builder. For further details, reference the Edelbrock cam instruction sheet or the AMC factory service manual. Enjoy the extra horsepower and the iconic bellow of your AMX’s V8.

External resources:
Edelbrock Performer RPM Cam for AMC
Summit Racing – Edelbrock AMC Cams
AMC Forum – Community Support