I ran 5.29's with a lockright in mine for 2 years. with 33"bogs and then 36SX's. I got on it plenty of times. I even bounced the rear up like 3 feet in the Air on a ledge once at full throttle(4cyl) came down and broke a Birf and bent a rear spring, but the rear end held up. But, my friend with a 904runner stripped 8 teeth off his stock 4.10 open V6 diff with 33's dont know how, I just pulled it apart to see the carnage, he said he was badly wedged in between some rocks and just floored it then all the sudden he popped loose and as he was driving to my house he heard all the noise. But like Camo said, I have me a pair of D60's to go under my 4runner with 39.5's and im only turning it with a pepped up TBI 4.3. I wheel down south here almost like the stuff you do(no mud holes for me), but wet slimy rock, and trust me with a 350, 39.5's and even a V6 third <IMG SRC="smilies/nuke.gif" border="0"> . It won't last long.