If your original mil. barrel is top shape, shining and crisp rifling, you could ream a new chamber 8mm.X64mm. and nothing else to change.
I have the same rifle that I rechamber 20 yrs a go, I reload using 06 brass, need to be fire form the first time, ( after trimming the shoulder is 1mm shorter than specs ) use only norma 196 gr. bullets on top of a compress load of IMR4831.
I am very satisfy of the performance, could bench 2 boxes of cartridges and the combined score fit inside 1,5" circle at 100 yrds., and on a bad day 2". I still have the original mil. trigger on it.
Since the 8X64 has the shoulder more forward than the 06 it has more powder capacity, and may be a little more power than the 30.06