I doubt you will have enough barrel wall thickness on a Kimber for a rebore. My understanding is you want minimum .15" on a side over bore diameter. What is an 84L, like .550" at the muzzle? Even if it does work out, the balance would be absolutely terrible.
Rebarreling with a heavier contour would work.
Though, the Ruger idea sounds like the best route for a factory 35 Whelen.
