you don't need 60s.
hell, a stock 29 spline 8.25 will do 35s as long as you're not stupid, so will the D30.
I've been beating on a D30 with 34/35" tires for a long time now.
I can understand the do it once mentality, but 60's is just plan absurd with 35's.
This is my unsolicited opinion:
If it were mine, I would stuff an 8.8 in the rear to replace the D35, get the disc brakes and a strong axle. Stuff a lunchbox locker in the 8.8 (Oh noes, the weak stock carrier!) and beat on it until something broke. Carry some spare front shafts and not worry about it.