I know quite a few guys running 33's(255/85/16) on their D2 and stock gearing. They don't seem to mind.
I would NEVER do gears without adding a locker at the same time. It's actually LESS work to add new gears to a new locker than it is to add gears to and old open diff. The set up cost for either should be the same.
4.11 gears are extinct. It's 4.12 now or 4.14 and both are stronger than the 4.11.
A locker will not only provide extra traction but is also MUCH stronger than the stock open diff. A huge benfefit with larger tires.
HD axles are needed if you install a locker.
Bigger tires, gearing, lockers, and HD axles are kinda like the 4 Amigos.
Now that said, 255/85 tires, working Traction Control, and decent suspension travel will get you pretty far.
I say put them on and see how you like it, I think you will. Just don't drive like a redneck.

 

Yeah, my disco is a slow vehicle for sure but not a concern.

So Im kinda confused. I may consider a set of 31 10.5 but found a set of Super Swampers that are 31 11.5. A friend of mine said that the 11.5 would be wider but not as tall as the 10.5?

 

i always use this Tire Size Calculator
it gives the dimensions both metric and "s so you can get an idea per manufacturer. if your manufacturer is not listed you can go to their website. it will tell you.

 

Thanks Dusty, looks like I cant even use these tires anyways on 16x7 rims. This tire crap is driving me nuts. Just wanted a wider tire with a inch or so more height from my 255/65....

 

265/75/16 and you'll be happy. They'll fill the wheel well nicely with no rubbing and the truck won't be a dog either.

 

a bit wider?

Noticed you have the rockstar bumpers on, do you have a winch? Im trying to figure out if theres a place for one.

 

don't listen to brett, all he knows is breaking windows and 35s.

265/75, 255/85, or 285/75. You'll be happy with the second two but the first one will get you places.

 

I'm gonna second this. I have 265/75R16 BFG AT KO and I really do like them. They aren't too big and they don't make it so sluggish that regearing is a must.

 

I am running 285/76/16 super swamped ssr tires and it runs ad drives fine on the road
off road is also fine the low range has good reduction
don't get me wrong I plan on lockers and when I do I will re gear
Check lucky 8 that have a. Good program where they will send you new ( pumpkins)
All you do is slide axles out and exchange the pumpkin and no downtime on your truck
You just return your core

 

33" super swampers... drives "fine" on the road. Guess we all have different definitions of "fine"

Lucky8 builds great diffs.