Edelbrock 5426 User Manual

C-26 AND RPM AIR-GAP DUAL QUAD VORTEC INTAKE MANIFOLDS

For 262-400 c.i.d. Chevrolet V8 with Vortec Cylinder Heads

Catalog #5426 & 7526

INSTALLATION INSTRUCTIONS

PLEASE study these instructions carefully before beginning this installation. Most installations can be accomplished with common tools and

procedures. However, you should be familiar with and comfortable working on your vehicle. If you do not feel comfortable performing this
installation, it is recommended to have the installation completed by a qualified mechanic. If you have any questions, please call our Technical
Hotline at: 1-800-416-8628, 7:00 am - 5:00 pm, Pacific Standard Time, Monday through Friday or e-mail us at [e-mail]..

IMPORTANT NOTE: Proper installation is the responsibility of the installer.

Improper installation may result in poor performance and engine or vehicle damage.

PLEASEcomplete and mail your warranty card. Be sure to write the model number of this product in the "Part #____" space. THANK YOU.
DESCRIPTION: The Edelbrock Vortec Dual Quad and RPM Air-Gap Vortec Dual Quad intake manifolds have been designed for 283-400 c.i.d. Small

Block Chevrolet V8 engines with Vortec style heads. They combine two small four-barrel carburetors with a dual plane manifold layout to achieve
the best balance of drivability, great looks, and outstanding performance for muscle car, street rod and marine applications. #7526 features an
Air-Gap design, separating the runners from the engine valley for a cooler, denser air charge. It stands 1-5/8” taller than the 5426 and it’s larger
runners offer performance improvements in the 1500-6500 RPM range. Edelbrock has developed special air filters for these manifolds. To give
your engine the ultimate custom look, the polished aluminum Elite Series oval air cleaner #4235 is suggested. Chrome oval air cleaner #1235 or
two #1209 (6" round) Pro-Flo air cleaners are also available. Please note Bracket section below for your particular installation.

• ACCESSORIES & INSTALLATION ITEMS: Major recommendations are listed below. See our catalog for details. To order a catalog, call
(800) FUN-TEAM, or visit www.edelbrock.com.

• EGR SYSTEMS: These intake manifolds will not accept stock EGR (Exhaust Gas Recirculation) equipment. EGR systems are used on most
1972 and later model vehicles. Check local laws for requirements.

• THROTTLE & ACCESSORY BRACKETS: The throttle and kickdown bracket on some vehicles may require modification to fit. These manifolds
will not accept 1968 and earlier alternator bracket assemblies and have no provision for ignition coil mounting. Use progressive linkage kit
#7094 to connect the carburetors together (See “Carburetor Recommendations”).

• CARBURETOR RECOMMENDATIONS: Use two manual choke carbs (Two 1404’s or two 1804’s), or one manual and one electric choke (1403
& 1404, or 1803 & 1804, if electric choke is desired). Note that the Thunder Series carburetors listed under manifold #7526 are calibrated
specifically for the 7526 manifold, and in most cases, will not require additional tuning. For manifold 5426, see “Prep and Tuning for Power”
for additional tuning information.

5426:

CARBURETOR CHOKE TYPE PARTS REQUIRED FOR INSTALLATION
Performer #1403 (500 cfm) Electric #7094 Dual Quad Throttle Kit, #8088 Dual Quad fuel line kit
Performer #1404 (500 cfm) Manual #7094 Dual Quad Throttle Kit, #8088 Dual Quad fuel line kit

7526:

CARBURETOR CHOKE TYPE PARTS REQUIRED FOR INSTALLATION
Thunder Series #1803 (500 cfm) Electric #7094 Dual Quad Throttle Kit, #8088 Dual Quad fuel line kit
Thunder Series #1804 (500 cfm) Manual #7094 Dual Quad Throttle Kit, #8088 Dual Quad fuel line kit

NOTES: Carburetors each require #8008 or #8024 stud, washer and nut kit. Determine proper length based on gasket thickness and your
accessory mounting requirements. If two manual choke Performer Series Carburetors are used and electric choke is desired later on, they can be
converted to electric choke using Electric Choke Kit #1478. Use electric choke on the rear carburetor ONLY. Manual choke Thunder Series
carburetors CAN NOT be converted to manual choke. If electric choke is desired with Thunder Series carburetors, a manual choke carburetor
should be used in the front and an electric choke carburetor should be used at the rear.

Catalog #5426, 7526
Rev. 1/06 - RS/mc

©2006 Edelbrock Corporation

Brochure #63-0271Page 1 of 2

• GASKETS: Do not use competition-style intake gaskets for this street manifold. Due to material deterioration over time, internal leakage of
vacuum, oil, and coolant may occur.

INTAKE MANIFOLD REFERENCE RECOMMENDED GASKET
5426, 7526 (None) Edelbrock #7235 Port: 1.08” x 2.11”, .120” Thickness

NOTE: To ensure maximum performance and a proper seal, Edelbrock gaskets which are

specifically designed and manufactured for use with Edelbrock parts must be used.

• SPECIAL NOTE: This intake manifold is primarily intended for use with Vortec-style heads on pre-Vortec blocks. Standard engine blocks
route the thermostat bypass water from the block directly to the water pump through the passenger side water pump mounting flange. If the
manifold is used on a 1996 or later Vortec engine that does not have the in-block bypass passage, you must route a thermostat bypass hose
from the water bypass port on the front of the intake manifold to the 5/8” hose nipple on the passenger side of the Vortec water pump. Use
a 3/8” NPT (pipe thread) to 5/8” hose nipple fitting, and a 7” length of 5/8” hose to accomplish this. If your engine block has the thermostat
bypass passage, use the 3/8” NPT plug supplied in the kit to plug the bypass port in the front of the intake manfold.

• PREP AND TUNING FOR POWER:
NOTE: Please refer to Edelbrock Performer Series Carburetor Owner’s Manual for detailed tuning procedures.

1. The 5426 manifold will produce optimum power and drivability when used with #1404 carburetors. Edelbrock has found, while dyno

testing our Performer 350ci (310hp) crate engine at our location, the best calibration to be: Metering Rods - .065” x .052”, Primary Jets

- .086”, and Secondary Jets - .095”. The 7526 manifold will see optimum performance with the use of 1804 carburetors. The 1804
carburetors are specifically tuned for the 7526 manifold and the stock calibration should be used. Calibrations will vary according to
engine build and atmospheric conditions. Use these recommendations as a starting point. Further tuning may be necessary.

2. Aftermarket distributor curve kits may be used with this intake manifold.

3. Use modified or high performance cylinder heads such as our Performer or Performer RPM.

4. Installation of aftermarket headers, camshafts or both may lean carburetor calibration. Should this occur, recalibrate with a richer jet.
CAMSHAFT AND HEADERS: Dual Quad manifolds are compatible with aftermarket camshafts and headers. Header primary tube diameter

should be 1-5/8” to 1-3/4" depending on the specific engine combination. Edelbrock has developed two camshafts for use with this intake
manifold - Performer-Plus #2103 or Torker-Plus #5002. Please check the catalog or website for rpm and application guidelines.

INSTALLATION PROCEDURE

1. Use only recommended intake gaskets set when installing this
intake manifold.

2. Fully clean the cylinder head intake flanges and the engine block
end seal surfaces.

3. Apply Edelbrock Gasgacinch sealant P/N 9300 to both cylinder
head flanges and to the cylinder head side of the gaskets, allow
to air dry, and attach the intake gaskets.

4. Do not use cork or rubber end seals. Use RTV silicone sealer
instead. Apply a ¼" high bead across each block end seal
surface, overlapping the intake gasket at the four corners. This
method will eliminate end seal slippage.

5. Apply removable thread lock, such as blue Loctite, to the intake
bolt threads. Install the intake manifold bolts. Carefully tighten
the intake manifold bolts evenly until the intake manifold has
lightly compressed the gasket.

6. Torque all of the manifold bolts in two steps by the sequence
shown in Figure 1 to 11 ft/lbs.

Figure 1 - 262-400 c.i.d. Small Block Chevy Torque Sequence

Torque Bolts to 25 ft/lbs.

Firing Order: 1-8-4-3-6-5-7-2

Turn Distributor Counter-Clockwise to Advance Timing

Catalog #5426, 7526
Rev. 1/06 - RS/mc

Edelbrock Corporation • 2700 California St. • Torrance, CA 90503

Tech Line: 800-416-8628 • E-Mail: [e-mail]

©2006 Edelbrock Corporation

Brochure #63-0271Page 2 of 2