IMO, do slightly more than just a Klune (which, personally, I'm not a huge fan of, having seen a few busted parts in them...)
Keep the 350....and the SM465...and run a Marlin doubler with stock gears to a minitruck back case. You'll save quite a bit of weight (that 205 is HEAVY) and keep the centered rear output, plus get a better initial low.
If you are running an offset rear diff, then swap in a split case from the 60/62 series with the Marlin in the middle. That was one of my initial choices...
How long is your front shaft now? Mine main shafts are both ~26" (front is 2-piece, first section is 13", 2nd is 26")