they sell a "Super 35" kit in various places, it comes with a detroit locker, strengthened shafts (i think), and an axle truss... It lists for about $995.
I broke mine, I'll tell everyone I know who runs above a 32" tire with any traction device to upgrade axles ASAP. It's completely useless wasting all that money "beefing up" the D35, when you could spend a little bit more money to buy a ready to bolt in 8.8, D44, Ford 9", or Toyota 8". I was one of those people who thought I could keep my 35 forever, until I airlocked it, threw 4.88's in it and hit some rocks... 2nd time out I broke the axle, ring&pinion, and broke the ARB. it took me about a second and a half after the "POW-SNAP" before I realized i had just spent $1200 for something that would break WAY too easy.
Sure, you'll see some morons still running a D35 with huge tires, but mark my words, it WILL break sooner or later. I'd rather have a different axle with the security knowing that it's NOT going to break rather than having to deal with the break again. That was a f-ing nightmare.