I can attest to this. I have the same model carb as you. While the floats weren't off much, I had to go with much leaner rods in the primary. I also had to purchase smaller jets for the secondary because the ones that came in the tuning kit still weren't small enough. The spring on the secondary flap had to be tightened up too as it was opening way too soon. Granted my 440 is a 77 so the tuning will be a little different but probably not too different. But now that I have it dialed in it runs very well and gets decent gas mileage.
