I drive an old Super Seven with 2 liters Ford OHC (105hp, ID NE, m.W. unmodified). When I bought the car, the engine was equipped with 48IDF carburetors (arg-adjusted) which I have barged for running, but I am not really satisfied. Although the 48IDF offers quite constant performance at the top, the “hole” in the lower speed range is finally quite pronounced. I do not drive the car on the track and do not look for the last HP in the above In the lower/medium range between 1,500 and 4,000 rpm, I want a fairly constant power, without starving up. In the net, I find both 40 IDF and 44 IDF hits. I feel that the jump from 48 to 40 is too big, so I think the 44 IDF is a good compromise. But before I install and vote the carburettors, I still have to set the Venturi size. They are supposed to make the biggest difference in performance. The 44IDF has 36 Venturi (-20% through) by default. If I would go to the 40IDF, the 28mm Venturi (-50% through) has experience. Does any of you really have the size of the Venturi with the power curve and which Venturi best fit the OHC? I have thought about building 34 Venturi. Then I would be in the middle / -30%. Does that make sense on the 2.0 Ltr OHC?