We are often asked what would be a good replacement for the Rochester B on a 261, and until today we suggested the Stromberg and Zenith carbs.
Was doing some research today on another subject and came across another anomaly with Carter carburetors. Normally, the "1" at the end of the model (W-1, WA-1, etc.) meant that the carburetor was an S.A.E. size 2 carburetor (no, I don't know why Carter didn't use a 2). Anyway, I found that Oldsmobile used a Carter WA-1 on some of the 257 CID 6 cylinder engines in the late 1940's. So I figured these should work well on a 261, but one would have to fill, drill, and tap the manifold for the size 2 carb.
Imagine my surprise, when checking the flange size, I found it to be a size 3 flange with 2 15/16 center to center! This means these carbs will bolt directly to the 261 intake, and are just perfect from a internal size standpoint.
I haven't had time to determine all of the various WA-1's that were used on this engine at this time.
The WA-1 was the top of the single barrel line for Carter until the YF came along (I personally still like them better than the YF).
The WA-1 has a conventional leather accelerator pump which is totally impervious to ethanol!!!!
The only possible drawback is that these carbs all come with a hot air automatic choke. However, it is easy to fabricate the necessary heat stove, I have directions posted on my website.
So now, those of you with 261's have a really good alternative.
Jon.
