It doesn't gets rough or struggles ignition/fuel its just takes much longer to rev higher than
5000 RPM as it goes from idle to 5000 RPM in second gear. It still builds up power as you can feel the difference if you shift at 5000 or 6000RPM. I had to change main jet sizes a lot so that it doesn't gets lean. It comes with 84 jets ootb. Holley Techs as well recommends to step up to a 1050 carb after reviewing all my specs.