DaveV, As you have observed the 261 only has two holes where as the Rochester Mono jet has four. If you go to U-tube Rochester rebuild (part 1 & 2), it shows the bottom of your throttle body. it does not look like it lines up with two vents on the Rochester model "B" which is the correct carb. for the 261. However if you can measure the throttle plate mounting hole's center to center I may have a gasket that will fit that I can send you. Other wise get a piece of blue typewriter copy paper and make an impression of the bottom of the Monojet and cut your gasket, line up with 261 intake manifold less two holes. To make it easy do a pencil rubbing of intake on white paper and see if the two hole's line up with two of the four holes of the Monojet. It is 4 a.m. here so I don't want to go out to the barn workshop now but I will check back with you this morning later and see how it's going. I may even have a 250/292 throttle body that will convert the fuel bowl to the new throttle body. Check back later. Doc
