Holley 1850-5

I like the AVS myself but the 1850 is a great carb also and will most likely need some tuning to get it perfect, it's a universal carb and that's why a lot of people don't like them, sometimes they don't work right out of the box you have to tune them.
or you can mess up the accelerator pump springs and get a off idle bog that can't be tuned out. Could be something simple with your rebuild.