hesitation when punching it.

I spent the night looking up all the parts in the holley carbs and how and what they do and then tore a spare down that I had in the garage. I have a basic knowledge of how it operates now. I'm going to order a 50cc accelerator pump to replace the 30cc one. I'll order a new powervalve (2.5) and mess with the jetting as well.
How do I know what size squirter to order? Should I just go up 2 sizes and see how it does?