My 261 in the altered runs an Offy three carb manifold intended for single barrel Rochesters. Last year I ran 3 x 97s using an adapter from Charlie Price. I found the engine over carburated. I have a set of Rochesters which I want to use but I do not want to use the original throttle linkage but rather the Lokar cable that I used with the 97s. Before I get myself into too much trouble, this is what I am doing. I have made adapter plates to rotate the carb 90 degrees putting the linkage parallel to the block. I will run a fuel line between the carbs and the head again parallel to the engine. I don't have flow numbers on the two types of carbs, but this should definitely make my CFM smaller. So far the setup is coming together rather nice. Now my question. By turning the Rochester sideways, will the operation of the carb be impacted?

As always, thanks
Warren

3 x 97 progressive (center primary) or simultaneous?
If progressive, have you tried changing the opening ratio (when the secondaries begin)?
My data, both rated @ 1.5" Hg (as 4 bbl.):
Stromberg 97: 117 CFM
Model B, 8 sizes (3 with 2-11/16" flange, 5 with 2-15/16" flange) ranging from 95 to 195 CFM each
Only the 216 Model B is smaller than a 97.

Panic, if you have the information, could you please post the Venturi , throttle blade, and cfm of the 8 model B carbs? There was an old thread where member Deuce Coupe posted some of the sizes, but it sounds like you have a more complete list.
As far as I know of there are only 3 sizes of the later model Monojet. As to The OPs question I don’t think it makes any difference which way the carbs are turned. In my own case, when I switched to a dual jet, the throttle blade opens the opposite way that the mono jet did. It was as if I turned the stock carb 180 degrees. A lot of guys that run a single 4 bbl carb have run it both front to back and sideways, they say no difference. Jay

It's in a Word table that won't post.
M: 3 sizes 160-250 CFM @ 3.0 Hg.". This assumes that the total carburetion is small enough that the engine will pull 3.0" of WOT vacuum. If not, the actual CFM will be less. With large sizes multiply by .7071 to get the CFM @ 1.5 Hg.". For intermediate WOT vacuum, use the square root of the ratio of actual vacuum to 3.0 times the 3.0 rated CFM.
Depending on the carb and manifold the difference may be very small at WOT but give bad distribution @ part throttle.