I'm running two NOS Rochester 1 bbl. carbs on my 261 through an Edelbrock 2 x 1 intake. They are small base carbs NOS carbs. I have made it a point to be sure I have no vaccuum leaks and that they are jetted as small as possible without sacrificing performance. I also recently have discovered that the small 1 bbl. foreign made chrome air cleaners with the small paper element do not allow enough air to enter the carb throat and they tend to choke the carbs. I have moved to a larger air cleaner set up and it has improved gas mileage.
