Hi Angela, Mal knows where I was heading!
The Outer diameter of the bushing, minus the outer diameter of the tube, divided by 2 equals the amount of "material" available for us to play with
(easier than abstract harmonic analysis, Doc!).
So, some examples:
Executive Kit: .420" - .368" = .052"/2 =
.026" (to play with).
Sierra (Berea): .474" - .410" = .064"/2 =
.032"
Knurl: .472" - .368" = .104"/2 =
.051"
Sierra Vista (Berea): .551" - .410" = .141"/2 =
.070"
Please check my math, not my strong suit! But you get the idea - you picked a very nice kit, but one that has a small amount of material at the ends. I compensate with end caps. You can also have a pronounced bevel to the profile. You chose to have a fairly even match to the bushing OD - KUDOS, as you had a small margin of error.
Again, well done and I really welcome your creativity!