Visual comparison on various Ford 3x2 setups
- AirFuelSpark
- Nov 13
- 3 min read
260/289 vs FE setups.
First a chat about the different sbf carbs:
I was asked via email about the 260 and 289 3x2 carbs.
Basically a guy was shopping for some and needed info to make sure he was making a wise purchase.
So lets have a talk.
mid 1963 is the earliest I’ve seen an over the counter 260/289 Ford 3x2. I have seen them as late as early 1967.
These were very small.
The 260 setup:
Primary carb C4GF-9510-H List 2867
Metering block 3673
47 jet
Outboard carbs C4GF-9510-J List 2868
Metering block 3563
53 jet
These had a venturi of 1.025 inches and throttle bore of 1 7/16 inch. They took a 103 throttle plate.
The 289 setup:
Primary carb C4AF-9510-U List 2881
Metering block 3673
53 main jet
Outboard carbs C4AF-9510-V List 2882
Metering block 3563
51 jet
These retained the 1 7/16 throttle bore but had a 1.045in venturi.
The primary carb had a power valve the outboards do not.
Calibration wise they work fairly well as is and are fairly “normal,” although the mixture screw feed holes are pretty small.
When I say mixture screw feed holes, I mean the hole that the mixture screw seals.
On a typical Holley this hole is .062 or thereabouts. On these the hole is .058 primary and .048, so the idle fuel is curbed by design.
What this means is that on a larger engine or with a camshaft providing more overlap, you may come to a point where opening the mixture screws further has no effect.
The booster feeds are also self limiting.
A typical generic straight leg carb has a .139 angle channel and a .140 booster size.
On these the booster pins are .119 and .98, angle channels are also comparably smaller.
What this means, at some point larger jets will have no effect. It also provides different characteristics to how the engine draws on the fuel in the main wells.
Fe baseplates (if original) have no provisions for vacuum advance. So if you see the hole open on the metering blocks, it is because it goes no where. With 260/289 carbs there is often a vacuum advance for primary only, so pay attention when building baseplate.
Every transfer slot has a tiny .024 hole at the bottom of the slot.
This provides a good bit of fuel at idle, prevents the outboard carbs from having stale fuel, and also keeps the idle circuit active on those outboards if the throttle plates are fully closed.
Primary throttle shaft lever is unlike the FE Galaxie setups and are like the Thunderbird setups.
Linkage and fuel logs are also unlike the FE types and are specific to the 260/289s.
Early intakes often have no labelling, part number, and often no date. Later ones are more desirable and are cast with “Buddy Bar” on the underside.
On the earliest 1963 carbs it is very common to see odd looking stampings, and a lot of variation in the choke horn markings. This is not a cause for alarm and appears to be normal.
All fuel bowls had a full time external vent with a metal cap on them. As is the case with all Ford 3x2 setups the primary fuel sight plug location is at a normal height and the outboards are set very low.
When purchasing cores, understand that there is NO correct replacement for these bowls. Generally speaking the easiest way to find a correct bowl is to purchase an entire carb.
Although on smaller engines these setups provided a power boost in stock engines (the stock carb sizing was tiny), in today’s world, these should not be considered appropriate for max effort cars.
What they are great at is providing a decent amount of airflow while allowing you to cruise on a single 2v carb. In a case like this, the usable power is likely too low to really show up on a dyno. I can say from experience that these are a ton of fun on the street as they are very torquey.
Plus they look badass.
Here is a video discussing them:
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