You may have misunderstood my comments a bit, Sock vs Stock without opening it up to install or replace a single part was the basis for my comments. I to have owned and worked on dozens of 8.8's from my younger years working in mustang specialized speed shops and than 25 + years of having owned and raced 8.8's in my own 5.0 Mustangs. It needs to be said that a majority of the 8.8's DO NOT have 31 spine axles, all the '"car" axles had 28 spline and it is not overblown a bit about the C-clip issue. I have seen first hand 8.8 & 7.5 axles that would break and walk out of the later disc brake SN-95 mustangs, it was also discovered back 20 + years ago the factory disc brake rears where weaker than the drum brake counter parts, these axles would often snap somewhere out by axle tubes ends, my 95 Cobra that barely made 300 hp broke two right side axles alone. Additionally you mention the axle tubes, one of the first agenda items for the rear when we built an 8.8 for a 500+ hp mustang (or a car with traction) was weld the axles tubes since only quarter sized spot weld retained them, up until recently I had a "bent" housing where the tube was pulled and twisted laying around till the wife asked my to take it to the scrap yard...
To summarize, both are fine axles and I have even installed an 8.8 in my old YJ but in my honest opinion i can't say one is stronger than the other stock vs stock.
I was talking stock to stock... Perhaps you misunderstood?
3.25" tube diameter is significantly stronger then 2.62"... STOCK TO STOCK
The gear set is also much beefier STOCK TO STOCK.
My point was that the rest of the weaknesses are
EASY to circumvent, its certainly easier to eliminate C clips then change your tube diameter and your not changing the gear set for a beefier one. The C-Clip "problem" isn't likely to bite anyone right away if ever. If it does pop out it often times just falls to the bottom of the dif.
There are plenty of mild 600 HP+ 4,000 pound curb weight Coyote 5.0s running around on the 8.8, there are plenty of C-Clip 8.8s in use on these "mildly built" cars running deep 10 and high 9 second E/Ts. My buddies and I own some of them; I have spent a lot of time at the strip and the amount of failures certainly aren't overwhelming. Hell the bolt on N/A ones are seeing 400-450 WHP...
They stopped using 28 spline 8.8s on the Mustang GTs back in 2005 dude... lol.
Most of the later explorer axles with disc brakes that I have found have 31 spline axles (1995 and up lol)...
Welding the tubes to the housing isn't just practice on the 8.8 but is pretty well known, no news there and again not a big deal.