VX80 rear diff upgrade

[mudlva]

Im now targetting the rear diff on my little project here
The rear diff is out of a VX80 as std it has the strenghtening box section so that is all sorted

How much can i gain by shaving the pumpkin?
As im doing the Y60 in the front it is kind of leaning to doing something in the back as well

Second ? Is tge rear liwer arms are 43mm o/d tubing.
I know of pkenty of guys running the Y60 rear where the lower arms have bent under hard hill climbing loads. But they are also a lot smaller in o/d as well.
So. Has anybody heard or seen the rear arms off a 80 bend or buckle?
Prevention better than cure and if the arms do fail then generally you kiss the pinion good buy at the same time.

Thoughts?