Installing an Edelbrock Performer RPM intake manifold on your A-body Mopar is one of the most effective single upgrades you can make to unlock significant horsepower and torque gains. Whether you are building a street-strip 340 Duster, a 360 Dart, or a mild 318 Scamp, the Performer RPM manifold delivers a broad power band from idle to 6800 rpm. This comprehensive guide provides a detailed, step-by-step approach to ensure a leak-free, high-performance installation. We cover everything from tools and torque specs to gasket selection and final tuning adjustments, giving you the confidence to tackle this job in your own garage.

Tools and Materials Needed

Gathering all necessary tools and parts before you start prevents frustrating interruptions. For this job, you will need a standard set of mechanics tools plus a few specialty items. Using the right tools is non-negotiable for correct torque and bolt handling.

  • Edelbrock Performer RPM Intake Manifold (part # 60756 for LA small block, or your specific application)
  • Intake manifold gasket set (Fel-Pro 1205 or equivalent for LA small blocks; use printoseal gaskets for best sealing)
  • High-quality torque wrench (rated for 10–150 ft-lbs; calibrate if overdue for service)
  • 3/8-inch and 1/2-inch drive socket sets (metric and SAE; 3/8-inch drive for most manifold bolts)
  • Ratchet and extension bars (6-inch and 12-inch extensions helpful for reaching rear bolts)
  • Engine degreaser and shop rags (non-chlorinated brake cleaner also works)
  • Thread sealant (Permatex high-temp thread sealant or Teflon paste; never use RTV on intake bolts entering coolant passages)
  • Small tube of RTV silicone (black or red, high-temp; for applying a small bead at the block-to-intake gasket corners)
  • Flat-blade scraper or razor blade (for cleaning old gasket residue)
  • Pickle fork or gasket scraper (to separate stubborn parts)
  • Carburetor hold-down studs and nuts (your Edelbrock manifold may include them; verify thread pitch matches your carb)
  • Shop vacuum (for cleaning debris from intake ports)
  • Feeler gauges (to verify manifold-to-block alignment on factory squares)
  • Safety glasses and nitrile gloves

Preparation Steps

Proper preparation ensures the installation goes smoothly and the new manifold seals perfectly. Skipping these steps often leads to vacuum leaks, coolant leaks, and poor performance later.

Disconnect the Battery

Disconnect the negative battery terminal. This prevents accidental shorts from tools touching the starter solenoid, alternator, or any other live terminals while you work around the engine compartment. Wrap the cable end so it cannot accidentally contact the terminal.

Clear Access to the Engine

Begin by removing the air cleaner assembly, the carburetor (with all its linkages), and the distributor cap. Mark the distributor housing position with a permanent marker relative to the intake manifold so you can reinstall it with the same timing. Label all vacuum lines and wiring connectors with masking tape. Remove the alternator and power steering brackets if they interfere. On A-bodies, the heater box can be tight; sometimes you may need to loosen the master cylinder bracket bolts for extra clearance. Take photos before disassembly for reference.

Drain the Cooling System

Place a drain pan under the radiator and open the petcock. Typically, you only need to drain about 3–4 gallons of coolant to drop the level below the intake manifold ports. Loosen the lower radiator hose clamps and slide the hose off the water pump connection if the hose passes near the manifold. Alternatively, remove the thermostat housing and drain from there. Having a half-full cooling system prevents a mess when you pull the manifold.

Removing the Old Intake Manifold

Removing the old intake manifold is straightforward if you follow a careful procedure. For early A-bodies (pre-1973), the manifold may be a single-plane or a factory spreadbore dual-plane. Take your time to avoid damaging the cylinder head gaskets.

Loosen the Intake Bolts in the Correct Sequence

The intake manifold bolts on a Mopar small block are 5/16-inch or 3/8-inch depending on year. Use a socket and ratchet with an extension to reach the center and rear bolts. Loosen each bolt in a reverse-sequence pattern – start from the outer bolts and work inward to relieve tension evenly. This prevents the intake from being pried off unevenly. Remove all bolts and set them aside; they will be reused only if they are clean and not stretched. (Edelbrock provides new bolts with the manifold, which are better.)

Lift the Manifold

Once all bolts are out, the manifold should lift clear by hand. If it resists, gently tap the sides with a plastic mallet from underneath. Do not pry between the manifold and cylinder head gasket, as this can damage the head gasket. Remove the old gaskets completely. Use a razor blade to scrape off any old gasket material stuck to the block deck surfaces. Be careful not to score the aluminum heads or iron deck.

Clean and Prep Surfaces

Clean the engine block decks and the cylinder head mating surfaces with brake cleaner and a lint-free rag. Spray degreaser and wipe again until no dirt or oil is present. Ensure the dowel pins on the block are present and clean. These alignment pins locate the intake gaskets. If any dowel pins are missing, replace them before installation.

Installing the Edelbrock Performer RPM Intake

The Performer RPM intake is engineered with a dual-plane design that separates the runner pairs to enhance low-end torque and throttle response. It is a direct bolt-on for 273-360 LA engines. The installation steps are critical for a long-lasting seal.

Gasket Selection and Installation

Use a Fel-Pro 1205 gasket set for most LA Mopar small blocks. These are printoseal gaskets that feature a rubberized bead that sticks to the manifold. Place the gaskets onto the cylinder head decks over the alignment dowels. Some builders apply a thin layer of RTV to the gasket end rails (the vertical surface at the front and rear of the block intake valley). Apply a 1/8-inch bead of RTV to the block at the four corners (where the metal meets the China wall). This prevents external coolant leaks. Do not put RTV on the entire gasket; only the corners.

Install the Intake Manifold

Carefully lower the Edelbrock Performer RPM manifold onto the gaskets. It should settle easily onto the dowels. If it binds, do not force it; lift it and check for gasket misalignment. Once seated, install the two front and two rear bolts finger-tight only. Do not tighten any bolt yet. The manifold should sit flat on the block rails. Use a feeler gauge to check that the manifold is centered on the cylinder head ports and does not shift side-to-side.

Torque Sequence and Specifications

Follow the Edelbrock recommended torque pattern: begin with the center two bolts on each side, then work outward in a crisscross pattern. The specified torque value for the Performer RPM on a small block Mopar is 35 ft-lbs for a cast-iron block with aluminum manifold. Never exceed 45 ft-lbs, as this can warp the manifold or strip threads.

Here is the tightening sequence step-by-step:

  1. Install all bolts hand-tight.
  2. Tighten the center two bolts on the left bank (driver side) to 5 ft-lbs.
  3. Tighten the center two bolts on the right bank (passenger side) to 5 ft-lbs.
  4. Move out one bolt on each side (the second pair outward) and tighten to 5 ft-lbs.
  5. Continue outward until all bolts are at 5 ft-lbs.
  6. Repeat the entire sequence at 15 ft-lbs.
  7. Final pass at 35 ft-lbs, using the same pattern.

Important: Apply thread sealant to the bolts that go into the coolant passages. On LA small blocks, the eight inner bolts on each side do not enter coolant, but the outer four bolts do. Check with your specific manifold; when in doubt, seal all bolts. Use Permatex or equivalent high-temp thread sealant, not Teflon tape, as tape can clog oil galleys.

Check for Alignment

After torquing, verify that the manifold gasket material is not squeezed out and that the bolt holes are not distorted. Look at the gap between the manifold and the block at the China wall (the front and rear). A uniform gap of about 1/8-inch is normal. Run a straightedge across the manifold-to-cylinder head surface to ensure it is flat.

Reconnecting Components

Now reassemble all removed components in the reverse order, paying attention to routing and torque.

Install the Carburetor and Linkage

Mount the carburetor on new studs (included with the Edelbrock manifold) or reuse the originals. The Performer RPM is designed for square-bore carburetors. Use an Edelbrock carburetor base gasket and a spacer if desired. Tighten the nuts evenly with a cross pattern. Reattach the throttle linkage and kickdown rod. For Mopar A-bodies, adjust the throttle linkage so that the carb opens fully when the pedal is floored. Check for binding.

Reconnect Vacuum Lines and Cooling Hoses

Attach all vacuum lines per your labels. For distributor vacuum advance, hook it to a ported vacuum source on the carburetor (above the throttle plates) for street use. Reinstall the thermostat housing with a new gasket and sealer to prevent leaks. Refill the cooling system with fresh 50/50 coolant. Reconnect the battery and verify all electrical connections.

Install the Air Cleaner and Final Connections

Install the air cleaner assembly. If using an aftermarket filter, ensure the rubber snorkel does not contact the manifold or booster. Re-attach any ground straps that were removed.

Final Checks and Testing

Before starting the engine, perform a thorough inspection to catch mistakes.

Check for Leaks

Look around the intake manifold gaskets at the front and rear China walls. Run your finger under the manifold edges to feel for coolant or oil. Check the carburetor base gasket for fuel leaks. With the engine off, tighten any hose clamps that appear loose.

Initial Start and Idle Adjustment

Start the engine and let it idle at a fast idle (about 1500 rpm) for 10–15 minutes to bring the engine to operating temperature. During this time, inspect for smoke or steam indicating a coolant leak. Check the oil dipstick for signs of coolant contamination. If everything looks good, adjust the idle mixture screws on the carburetor to achieve a smooth idle (typically 1.5 to 2 turns out from seated for Edelbrock carburetors). Set the base timing to the manufacturer’s specification (usually 10–12 degrees BTDC for stock cams, 14–18 degrees for performance cams).

Road Test and Tuning

Take the car for a gentle test drive. Listen for pinging or hesitation. The Performer RPM works best with a tuned carburetor. You may need to adjust the jets or the accelerator pump if the mixture is off. Check for vacuum leaks using a carburetor cleaner spray around the manifold gasket area (if the engine idle speeds up, you have a leak). Re-check the intake bolt torque after the first heat cycle – some bolts may require an extra 2–3 ft-lbs.

Performance Benefits

After a proper installation, the Edelbrock Performer RPM intake provides substantial improvements over an OEM intake. Expect a 15–30 horsepower gain on a 318, 340, or 360, depending on the camshaft and carburetor combination. Throttle response sharpens significantly due to the dual-plane design that accelerates air-fuel mixture velocity. The low-end torque remains excellent, making this intake ideal for street-driven Mopars with automatic transmissions and relatively steep gears. For a high-performance engine, pairing the Performer RPM with a 650-750 cfm carburetor and a camshaft in the 210–230 degree duration range yields killer results.

Common Pitfalls and How to Avoid Them

  • Overtightening bolts – The Edelbrock aluminum manifold can distort if you exceed 35 ft-lbs. Use a calibrated torque wrench.
  • Incorrect gasket selection – For LA engines, the Fel-Pro 1205 is a proven choice. Never use the thin fiber gaskets that come with some budget sets.
  • Forgetting thread sealant – Coolant leaks from the manifold bolt holes are a common failure. Apply sealant to every bolt that enters a coolant passage.
  • Not allowing the RTV to cure – If you use RTV at the block corners, give it 24 hours to cure before running the engine. Alternatively, use a fast-cure RTV (like Permatex Ultra Black) and wait at least 1 hour.
  • Skipping the heat cycle re-torque – Always re-check bolt torque after the first 20-minute hot run. Bolts can loosen as the gaskets compress.

Conclusion

Installing the Edelbrock Performer RPM intake on your A-body Mopar is a rewarding project that delivers real-world performance gains. With careful attention to gasket placement, torque sequence, and a methodical reconnection process, you can achieve a professional-quality installation in a home garage. The result is an engine that pulls strongly from idle to redline, with improved throttle response and a deeper, more aggressive sound. Refer to the Edelbrock official installation instructions for your specific manifold model, and consider joining a Mopar A-body forum for additional community support. For comprehensive torque specs and technical data for your LA small block, consult Engine Builder Magazine. Take your time, work cleanly, and enjoy the enhanced driving experience.