But the thing is, the springs set on top the axle, so no matter what you do for springs the differential/shock mounts don't get higher, and that's the low point that's most likely to get hung up. So I'm not sure I see the point of the lift in and of itself. It would increase the angle of attack/departure slightly to the better. It wouldn't change the ramp angle though. It would decrease stability.
Get to know your 4x4! (euro4x4parts.com)
I see all kind of super expensive trucks (like a Super Duty FX4) but when you look under them it doesn't look to me like they have any more clearance to the differential than my truck.
The only way you get more clearance is bigger tires, and there's a limit what you can do there without hacking up / replacing fenders and all the other issues like rubbing in turns, and if you go really big you'd probably want a different final drive ratio, ideally, if it's possible but I realize that's a bunch of work.
For me it seems like one major issue is even if I'm not in a could-high-center situation, so far the most common thing that happens with me is crossing streams; the differential(s) is likely to get in the water, if not from the water depth then from the fact flowing water piles up against anything it hits. So probably the first thing I should do is run tubes up from the differential vents, one guy posted how he did this between the cab and bed with a little manifold, I think it was, to keep water out of the tube ends (I think). I got to get in my manual and find how to check fluid levels on diff's and xfr case which I obviously should have done already. When I eventually get around to putting on 31" (oem size) tires that will gain me about 1.5" height (an inch, plus, the 235's are pretty worn so some height loss there too) which doesn't sound like a lot be every inch counts.
There's a limit to how much water you can drive through, of course, but what happened to me was I did like four or five crossings then one (the one I stopped at last time) I thought the water would be shallower but it was deeper so I still didn't get across because the getting across wouldn't be an issue but at the far side it looked like 10" deep moving water then it climbs up out of the creek (like they almost always do) and there's an upthrust of bedrock there which probably I can navigate but I just thought I'd rather do it with not so much water until I really know wtf I'm doing. Point of that is, I'm going to be in water, and one I came out of then got that "chink" sound metal makes when it's quickly cooled so I know something was getting wet under there. Anyway, navigating that stuff is a matter of what the truck can do and I'm not really sure what that is in its current form, but I think once I get the tires on that will help some. All I know is, sure there are cross-members and skid plates, but there's a whole bunch of stuff under there that you really don't want dragging over a rock point.
Here's a really sharp truck and you can see it has appreciably more clearance under it - not unlimited (differential). Not sure what the tires are but for sure not oem. So if I had that truck then I would have gone right through that crossing no problem. Now if I could set my truck up like that I'd be happy.
I think I'm looking at some money in the front suspension and custom body panels on there. I'm thinking of getting those tires they say they're not horrible noisy. I'm guessing those are probably 33" tires on 15" rims.