If so, you may not be able to move the gas block back. Although I have not taken exact measurements, from doing SL8 barrel conversion I suspect you may run into the following issues...
1) Early K barrels with the "round" gas block style... the ID of the block is more than likely just slightly larger than the OD of the barrel. If so, I would VERY strongly not recommend sleeving it.
2) Later K barrels with the "block" gas block style... the ID of the block is too small so the muzzle end OD will be too small for proper FH friction, although you can develop an alternate menthod to lock the FH in place.
For $375 plus return shipping, I can convert an SL8 barrel to C spec. If your K barrel is factory, you could sell it, ship me an SL8 barrel for proper conversion and still have $$ left in your pocket.
In any event, here are the measurements you are looking for...
Gas port hole 0.0790"
Gas port hole center from muzzle 1.2550" (approx.)
** I don't have long enough mics here at home to measure from the breech.
When I convert barrels, I measure (and verify) placement of the gas block first and then center the gas port hole based on that. That way I am guaranteed that the gas port hole is correctly aligned with the gas block. My measurements are based on moving an SL8 gas block so what I have will probably do you no good (assuming you have a factory K barrel).
Hope that helps.