Spread Port Tunnel Ram Intake Manifold    SMWTR1

The SMWTR1 manifold is designed to deliver the highest performance and value for Big Block Chevrolet Spread Port engines.
The runner length is tuned for engines operating up to 7,500 RPM.
Total weight with top 29 lbs.

A precision cast manifold will perform the same or better than a fabricated manifold of the same target dimensions for the following reasons:

1. Reduced resonance from vibration.
2. Runner cross sections of a casting are more precise than welded sheet metal.
3. Runner cross sections of a casting have better shape transition from rectange to round than formed sheet metal.
4. Material is provided near the openings for port matching where it is needed.
5. Runners have matched radius turns rather than bevel connections for smoother flow.
6. More accurate runner to plenum blend radii.

Fitting the Manifold
The manifold is delivered with stock on the mounting faces so that it can be custom fit to your heads.
There is only one version of this manifold.

Standard Spread Port Heads
This manifold can be fit to the heads listed below with 9.8 or 10.2 deck height blocks without spacers:

  • Brodix:
    - PB1200 Series (Big Duke)
    - PB1800 Series (Big Duke)
    - PB1803 Series (Big Duke)

  • Dart:
     Big Chief:
    - 14 Degree Oval CNC
    - 14 Degree Rectangle
    - 18 Degree Rectangle Pro 1

    Raised Port Heads
    Spacers are required to fit this manifold to these raised port heads when they are used with 10.2 deck blocks.

  • Brodix:
    - PB 2005 14.5 Degree

  • Profiler Performance:
    - Hitman 12 Degree