Customs Holley Carb issues!

You can buy small Jets that are threaded 10/32 and can be used for air bleeds or idle discharge , I've never wanted to risk screwing up a good carb trying to put them in . I've also seen 6/32 motorcycle/ small engine Jets ... There's even some guys will cut brass screws and drill thier own without a flowbench or engine Dyno , I'd think it would be Really hit or miss ...