Why Choose the Edelbrock RPM Intake for Your B‑Body Mopar?

The Edelbrock RPM intake manifold is one of the most popular aftermarket upgrades for the Chrysler B‑body platform — think 1960s and early 1970s Dodge Charger, Plymouth GTX, Road Runner, or Super Bee equipped with a 383, 400, or 440 big‑block. Designed to deliver strong torque across a broad rpm range, the RPM series manifold helps unlock significant low‑end and mid‑range power. A properly installed Edelbrock RPM intake on a B‑body big‑block can add as much as 50 ft‑lb of torque at the wheels, often accompanied by a 20–30 hp gain, depending on the rest of the engine combination. However, realizing those numbers requires careful installation, correct gaskets, proper bolt torque, and thorough leak testing. This guide walks through every step to get you there.

Tools and Materials

Before starting, gather everything you will need. Having the right parts on hand prevents frustrating trips to the parts store mid‑job.

  • Edelbrock RPM Intake Manifold – For B‑body big‑blocks, the standard part number is EDL-7193 (non‑EGR) or EDL-7194 (EGR provisions). Verify compatibility with your cylinder heads and distributor clearance.
  • Torque Wrench – A 3/8‑inch drive, 0–75 ft‑lb range wrench is ideal.
  • Socket Set – Standard and deep 3/8‑inch drive sockets: 7/16, 1/2, 9/16 (many intake bolts use 7/16 hex or 1/2 on older castings).
  • Gasket Set – Edelbrock recommends using Fel‑Pro MS 98005 T or the specific intake gasket for your cylinder head port size. Avoid paper gaskets; use a composite or steel‑core gasket.
  • RTV Silicone – High‑temp, oil‑resistant RTV (e.g., Permatex Right Stuff or The Right Stuff Black) for the china walls (front and rear of the intake valley).
  • Engine Cleaner & Rags – Brake cleaner or a dedicated gasket remover to dissolve old residue.
  • Thread Sealant – Permatex #2 or Teflon paste on the intake bolt threads (especially for the four bolts that go into the water jacket).
  • Razor Blade Gasket Scraper – For cleaning the block and manifold surfaces.
  • Straightedge (12″ or longer) – To check deck flatness of the block.
  • Vacuum Gauge – Essential for final tuning and leak detection.
  • Distributor Hold‑Down Wrench – You may need to remove and re‑time the distributor.
  • Feeler Gauges – For checking distributor gear mesh and manifold‑to‑head alignment.

Preparation

Work on a cold engine. Disconnect the negative battery cable. Drain the coolant below the intake manifold level – usually draining the radiator and block drains is sufficient. Remove the air cleaner assembly, including the carburetor (if still installed) or throttle body, and any other components that block access to the intake.

Remove the Old Intake Manifold

Begin by loosening the intake bolts in the reverse order of the torque sequence – typically working from the center outward. This prevents warping the manifold. Use a socket and ratchet; be careful not to strip the bolt heads. After all bolts are removed, lift the manifold straight up. It may stick due to old gasket material. A gentle pry with a wooden wedge (never a screwdriver that can gouge the aluminum) helps.

With the manifold off, inspect the lifter valley. Clean any debris. Remove the old gaskets from the cylinder heads and the front/rear china walls. Use a razor blade scraper and brake cleaner. Take care not to score the aluminum cylinder heads or the block deck.

Check the Block and Head Surfaces

Place the straightedge across the cylinder head deck surfaces. Any gap larger than 0.005″ indicates need for machining. Also check the manifold’s mating face for flatness – the Edelbrock RPM is cast and should be true out of the box, but a quick check avoids vacuum leaks.

Prepare the New Edelbrock RPM Intake

Inspect the intake for any casting flash or burrs in the runners. Clean all surfaces with brake cleaner. Apply thread sealant to the bolts that will go into water passages – usually the four bolts at the front and rear of the intake. For other bolts, a light coating of oil is fine. Do not install the intake dry – the sealant prevents coolant leaks into the oil.

Some B‑body owners choose to drill and tap the manifold for manifold vacuum or for aftermarket accessories (like a PCV valve). Do this now, before installation.

Installation of the Edelbrock RPM Intake

Proper installation technique is critical to achieving the advertised torque gains. A vacuum leak or uneven bolt torque will cost you performance and may damage the gaskets.

Apply the Gaskets and RTV

Start by applying a 3/16″ to 1/4″ bead of RTV silicone on the front and rear china walls (the flat areas at the front and back of the lifter valley). Do the same where the china wall meets the cylinder head – a vertical dab at each corner. Then place the intake gaskets on the cylinder heads, aligning the bolt holes and port openings. The gaskets should be oriented so the printed side faces the manifold (some gaskets have a specific top/bottom or front/back).

Position the Manifold

Carefully lower the Edelbrock RPM intake onto the engine. Watch the distributor clearance – you may need to remove the distributor temporarily. As the manifold seats, the silicone will compress. Hand‑start all bolts. Do not tighten yet.

Torque Sequence

Using a torque wrench, tighten the bolts in a specific pattern to ensure even clamping. For Edelbrock RPM manifolds on big‑block Mopar, use a three‑step process:

  1. Torque all bolts to 10 ft‑lb in the center‑outward sequence (start at the intake center bolts, work toward the ends).
  2. Repeat sequence at 20 ft‑lb.
  3. Final pass at 25 ft‑lb for 5/16″ diameter bolts (most Edelbrock intakes use 5/16″). If your manifold uses 3/8″ bolts, final torque is 35 ft‑lb – check the manufacturer’s instructions that come with the manifold.

Important: Do not exceed 25 ft‑lb on the smaller bolts – overtightening can crack the manifold or strip the threads in the cylinder head. Also, do not reuse old bolts if they are stretched or corroded. Edelbrock provides new bolts with the manifold; use them.

Reconnect Components

Once the intake is torqued, wait the time recommended by the RTV manufacturer (usually 30 minutes to 1 hour) before starting the engine to allow the silicone to skin over. While waiting, reconnect:

  • Throttle linkage – Adjust so the carburetor or throttle body opens fully.
  • Vacuum hoses – Route them away from sharp edges. Connect manifold vacuum to the PCV valve, power brakes, and distributor advance (if used).
  • Fuel lines – Replace rubber sections that look cracked. Use steel lines where possible.
  • Coolant bypass hoses – The Edelbrock RPM has a thermactor passage; be sure to cap or route appropriately.
  • Distributor – If removed, re‑install with the rotor pointing to #1 cylinder. Set initial timing (typically 10°–12° BTDC for a mild big‑block).
  • Air cleaner assembly – A drop‑base may be needed for hood clearance on some B‑bodies; check before closing the hood.

Testing and Final Adjustments

After all connections are made, refill the cooling system. Reconnect the battery. Start the engine and allow it to idle. Listen for any hissing sounds indicating a vacuum leak. Spray a small amount of carburetor cleaner around the intake gasket surfaces – if idle changes, you have a leak. Tighten the offending bolt (do not exceed torque spec).

Checking Vacuum

Connect a vacuum gauge to a full manifold vacuum port. At idle (750–850 rpm on a mild cam), you should see 15–20 inches of mercury (in‑Hg) steady. A fluctuating needle points to a vacuum leak, incorrect timing, or a lean carburetor. Adjust idle mixture screws and timing as needed.

Road Test and Torque Confirmation

Take the car for a careful drive. Gradually increase load – the Edelbrock RPM will pull strongly from 1,500 rpm upward. Recheck the intake bolt torque after the first heat cycle: run the engine to operating temperature, let it cool, then re‑torque bolts to 25 ft‑lb (5/16″) or 35 ft‑lb (3/8″). This step prevents gasket relaxation. Expect a noticeable increase in low‑end torque – you should feel the extra 50 ft‑lb from around 2,000 rpm, especially on a B‑body with a 3.23 or 3.55 rear gear.

Performance Gains and Tuning Tips

The Edelbrock RPM manifold is designed for engines that operate from idle to 5,500 rpm. It offers a significant improvement over a stock cast‑iron intake, which is often restrictive. On a 440 with a mild cam (like the Edelbrock Performer RPM cam), a 750 cfm carburetor, and headers, the torque gain can approach the claimed 50 ft‑lb. To maximize results:

  • Match the carburetor – A 750‑800 cfm vacuum secondary carb works best.
  • Check distributor curve – The improved airflow may require a quicker mechanical advance curve.
  • Upgrade exhaust – Headers and a free‑flowing exhaust will let the intake work to its full potential.

Common Pitfalls and How to Avoid Them

  • Gasket alignment – The Edelbrock ports are about 0.060″ taller than some gaskets. Use Fel‑Pro 1205 or 1206 gaskets that match the port shape.
  • Distributor clearance – Some B‑body engines (especially with a tall cam or high‑rise manifold) require a smaller diameter distributor cap or a remote ignition module.
  • Hood clearance – The RPM manifold + a standard air cleaner may be too tall for factory hoods. Consider a drop‑base or a K&N X‑Stream filter.
  • Bolts into water jacket – The four corner bolts on many B‑body blocks go through the intake wall into the water jacket. Using thread sealant is mandatory – otherwise coolant leaks into the lifter valley.
  • Over‑torquing – A common mistake. Stripped threads in the cylinder head require heli‑coils. If you feel resistance before reaching torque, double‑check the bolt thread and hole condition.

External Resources

For additional details, reference these trusted sources:

Conclusion

Installing an Edelbrock RPM intake on your B‑body Mopar is a rewarding project that can dramatically improve torque and overall driveability. The quoted 50 ft‑lb gain is realistic with proper supporting modifications and careful installation. Follow the steps outlined here – clean surfaces, correct gasket choice, proper torque sequence, and final leak testing – to ensure your big‑block runs strong for years. Always consult your vehicle’s service manual for model‑specific details and always wear safety glasses when working under the hood.