I'd be somewhat hesitant to run 35" tires on a D30. 37" tires, I'd just expect every issue possible (can the brakes even handle that kind of tire at all?)
I sadly only have the D30 front, but it is built to the max inside. hardened shafts, arb, CTMs, etc. When i first bought my jeep, it had 37s on it, if you are not so right footed, you will be fine, but yes, it puts some strain on it.
I am currently running 35s (only because we thought the 37s were part of the death wobble issue...fixed now...wasnt the tires) and the axle works great! Would still love to have atleast a 44 in the front tho, but oh well. hopefully someday, some custom narrowed D60s, or something.