129 & 461 manifold question

[Michael Adams #31536]

Greetings,

I have seen both these intakes with two different carb intake openings. On one version the openings are both the same size. On the other, one opening is full sized and the other side has two smaller openings (Q-jet like). I have an early 63 340
car with a 129 on it that has the intakes both equal in size. I'm trying to get another one in better shape but I don't know what is "right". Can anyone set me straight? Why do the same castings have different intake configurations?
TIA...mike

[Wayne P.]

Re: 129 & 461 manifold question

129 is correct for your car. The 461 is for 1964.

[Terry D.]

Re: 129 & 461 manifold question

The one with two holes on one side and a larger oblong opening on other is correct. Back in the days, people would put bigger carbs on and hog out the manifold thinking it would increase horsepower.
Terry

[Chris D.]

Re: 129 & 461 manifold question

Mike,

In case you are comparing unaltered versions of these two part numbers, they are different because they mated to different carbs. Both should be three hole configuration with a big "combined" primary and secondary port on the passenger side. Your '63 AFB has secondaries slighly larger than the primaries for a mild spread bore effect. The '64 Holley had four equal size bores. The manifold ports (and end radii on the big port) were sized to match.