Two Plain 9 Super 7® Carbs to 4-Bbl Intake Manifold Adapter Kit

Rather than mounting a single 4-barrel carburetor, this adapter splits the job across two smaller three-bolt units, letting a Stromberg 97-style or Holley 94-style carburetor pair sit on a small Carter AFB or Holley 4-barrel intake flange. Air cleaners, a fuel block, fittings, red fuel line and a non-progressive linkage kit round out the box, and some assembly is needed.

What to check before buying

Both carburetors here act as primaries and both share idle duty, unlike a setup with a dedicated idle carb. Neither carburetor has a vacuum port built in, so plan on tapping the intake manifold itself if your accessories need a vacuum signal. Hardware for mounting, plus the pair of 3-bolt gaskets and a base gasket for the 4-barrel side, comes with the kit; the gasket between the adapter and the intake manifold is the one piece you'll need to source separately.

Dimensions

Figure about 10-1/2 in. from where the adapter sits down on the manifold up to the top of the air cleaners. The two carburetor centers sit 5-1/4 in. apart, and the adapter plate itself runs 1-5/8 in. thick.

How the carburetors are built

Each 9 Super 7 keeps the classic Stromberg 97 look and its 0.97 in. venturi, but trades the old needle and seat for a Grose-style fuel inlet valve, backed by a Nitrophyl float and Neoprene gaskets. Jetting mirrors a stock 97: .045 in. main jets with a number 65 power valve. Keep supply pressure between 1-1/2 and 4 psi, closer to 2-1/2 or 3 psi as the target; pushing past 4 psi tends to flood the bowls.