Application

The 1955 Thunderbird used the following carburetor numbers:

• Holley List 997; Ford ECJ-C (standard transmission)
• Holley List 998; Ford ECJ-D (automatic transmission)
• Holley List 1077; Ford ECJ-G (standard transmission)
• Holley List 1078; Ford ECJ-H (automatic transmission)

The carburetor illustrated is the 1078. The Holley `List`number (carb number) can be found on the rear of the base the carb. The Ford number may also be stamped in the back, sometimes with the generic carburetor number 9510 included. All Ford carbs include #9510, so ECJ-C is short for ECJ-9510-C.

The Holley Model 4000 is a member of the Holley 'concentric' series, which are carburetors that have a round float bowl elevated above the choke. More information and manuals are here.

Four barrel concentric carburetors were first used in 1953 and 1954 on Lincoln cars as the model 2140. The Model 4000 was introduced in 1955, and differs in that it uses a secondary diaphragm to open the secondaries instead of a mechanical linkage.

The 1955 models have a choke assembly mounted on the manifold below the carburetor. In 1956, the choke moved to a position integral with the carburetor body.

Restoring this carb

While the basic design of the carb is fine, restoring these can be challenging due to a number of factors. Often there is damage due to previous rebuilders. Many of these carbs were replaced over the years with aftermarket carbs. The original carbs were thrown out and are now being recovered from storage. Water damage is common.

For carbs in otherwise reasonable condition, the main problems with these - that can't be fixed with a carb kit - are that:

• the throttle shafts are loose - caused by wear in the brass shafts and/or the bronze bushings
• the float bowl cover is distorted, resulting in vacuum and fuel leaks

Finishes

The main body of these carbs is aluminum. When we restore these, we machine the base of the body flat as well as treating the body with a chromate solution which seals the surface and preserves the bright aluminum finish.

The float bowl and cover are zinc and are finished in an olive green chromate conversion coating.

>>More about the chromate finish

Most of the screws on the carburetor are Fillister head slot screws, except the choke plate screws which are binding head slot and the throttle plate screws which are a special undersize-head screw for Holley carbs only.

Parts for this carburetor from www.carburetor.ca