The IABs are in the .070 to .78 range.
If you have a numbered drill set, with no burrs on the shanks, they can serve as pin gages.
Or just shove some wires in there and measure later. LOL But that was how we did it when I first was learning. We had drilled the blades so they could close further and then it had no off idle power - it wouldn't make it up the hills at 30-35 mph. Came back to my coworkers house and stripped some wire down and stuck two strands in bleed. Worked great.
