I love my old FN 98 action Sako in 375 Wby. It is a viable long range rifle and can be a bit of a hammer with 350's if needed. It shoots factory 375 H&H well and is highly accurate.

I get 100-150 fps velocity increases over my 375s, and I've never had any extraction problems.

Is it worth doing? Yes if you have other 375s...No if it is your only 375. I use the 375 Wby for elk hunting, and some shots get out there a bit. My 375 Wby Sako/FN loves Nosler AccuBond 260 gr bullets, pushed a bit.