Offenhauser 1035 Intake Manifold 1950-1959 Chevy 6-Cylinder Dual Carb

Offenhauser Dual Carb intake manifolds provide a nostalgic appearance while equalizing fuel distribution to all cylinders, improving both performance and economy. With this lightweight cast aluminum manifold, your old “Stovebolt” will be more responsive across the RPM range. Use with two “big base” carburetors (2-15/16″ bolt centers) typical of 1954-62 Chevys.

• Fits 235-261 Chevy 6-cylinders
• 1950-1959 engines w/ PowerGlide
• 1953-1959 engines w/ Manual Transmission

Included linkage kit is “non-progressive,” meaning both carbs operate at the same time.

Notes

Note: This intake manifold is designed to bolt up to the heat box on your original exhaust manifold. Exhaust heat must be routed to the bottom of the intake to help keep the fuel droplets suspended in the air/fuel mixture, providing better cold weather performance and overall driveability.

To use water heat with your Offenhauser 1035 intake manifold, here’s what you need to know:

• The 1034 / 1035 manifold was originally designed to use exhaust heat from the stock exhaust manifold to warm the floor of the intake, helping with fuel vaporization. When you use headers, you lose this function.
• Some people run a water heat plate under the manifold, connected to the heater hoses. However, the 1034 / 1035 comes with steel freeze plugs installed in the heat passage underneath. These plugs are fine for sealing exhaust gas, but they will not reliably seal against water (coolant). If you try to run water through the heat passage as-is, it will eventually leak.
• To make the manifold suitable for water heat, you will need to remove the steel freeze plugs and weld in aluminum plugs to permanently seal the passage. Only after this modification can you bolt on a water heat plate and safely run coolant through it without leaks.

For the plumbing itself:

• You would tap into your heater core hoses for the inlet and outlet lines.
• Coolant flows from a T-fitting off the heater hose, through the heat plate under the manifold, and then back to the other heater hose or heater core.
• If you are not comfortable welding or making these modifications, you may wish to run the manifold without water heat, though cold-weather performance may be reduced.

Specs

• Carburetor Port Diameter:   1.700″
• Intake Port Diameter:  1.550″
• Carb Bolt Center-to-Center:  2-15/16″
• Head port flange:
  • 2.468″ (2 7/16″) Front to Rear
  • 2.315″ (2 5/16″) Top to Bottom