2" Bump stop plus lots of trimming.
The bumps are basically going to keep the tires out of the upper fender area and the frame/control arms. Your extra axle width will help out on the frame/control arms but not on the stuffed into the fenders clearacne. Your trimming is basically the body to account for the extra width of the tire.
40's look cool and will let unskilled drivers run over everything but they do have drawbacks and a lot of work to make them fit well.
Not that I had a problem with 37’s. I’ve said it before that life was good. Maybe too good on 37s. Good everything. Good road manners, good wheeling, good challenge. Easy to fit. They took me everywhere I wanted to go and then some.
Holding hands and first dates are way behind me now with respect to my relationship with 40’s. I’m fully committed to 71” tons and 4.5” BS beadlocks. I’m already picking names for my first new beadlock.
Width-wise, I feel like I am in a good spot. At least on paper. I don’t rub anything at all now with Nitto 37s. Metal Cloak arms are tucked in nicely, FWIW/FYI. Aired down MTR 37’s with mud in the lugs kissed the frame slightly. It was a gently, kiss-your-sister kind of kiss, though. The MTRs measured slightly larger than the Nittos.
I gain 5.5” total width (71-65.5=5.5)
Cut that in half to 2.75”
Going from 4” BS to 4.5” BS loses 0.5”, so now it’s 2.25”
40” tires are wider by 1” total. With an 8.5” wide Trail Ready @ 4.5” BS we can say I lose another 0.75” per side, leaving me with 1.5” of buffer there.
Upward travel, whether it be both wheels or one at full stuff and the other at full droop, I can see trimming the wheel wells as we have been chatting about in another thread.
I am really happy with the way the current lift works so I want to stay as close to that as possible. It will be a fine line between bump stops and the Sawzall.
My go forward plan on the bump stops is this….
Setup the front with the adjustable Kings to something equivalent to the 3” bump blocks with OEM stops up top that I have now. If the front tire hits the metal front fender tab then I will tweak up the up the King bump stops to compensate. Beyond that, I will trim back the front fender. I will report back in January once the deed is done. I feel that adjustment with the Kings will be easy for me to do.
On the rear, I am going to leave the 3” bump stop in place and cut out the wheel well openings. If it turns out that I need to add some bump stop, I’ll try to either bolt something onto the top of the fixed-height blocks or replace them with adjustables. Probably easier to just add some height to the 3”-ers. Anyway, I have a Milwuakee Fuel Sawzall with an LED headlight and a fresh set of blades. Let’s get jiggy. When I’m done, we’ll go with some tub-o-sealant.