Yes, you just have to drop the bowls to install mains, but better to pull carbs first if you have stock screws, as you will strip one or more if you're not real careful/ lucky!
Needle shims address a mid-throttle bog...
and... your screw kit. (just one option) http://newspeedmaster.com/html/carb_screw_kit.html


Howbeit when He, the Spirit of truth, is come; He will guide you in all truth: