MBSierra17

There aren't many lifts (that aren't actually just levels) at that height. You probably won't find anything comparable in cost either. Next step, at that height you want, would probably be to compare the leveling blocks to a set of decent coil overs and replace rear shocks. The only real difference between either of those level type kits and a "lift" is going to be geometry correction for uca, CV, and mayhaps a diff drop. That said, 2.5" in most cases doesn't require those so it's rarely done.

Stock. +27. Mine were at max height. Point isn't can 275's fit, point is that 305's very likely won't since 275's are very hit or miss. Also depends on which UCAs though.

Ah, if only someone would make replica wheels with more accommodating offsets. Many like the stock wheels, especially the snowflakes. And your math works, but tire manufacturers aren't quite that precise. One brand 285 might be 283,whereas another might be 286. Then there's the difference in how aggressive the sidewall lugs are. Lots of variables.

Sidewall made contact with front arm of the UCA.

Can't cut out the suspension and sway bar. +27 with 305 wide, I'd bet you rub more on the inside than you do out.

Stock 20s rub on the front arm of the UCA's. I'm lifted now, so don't have that problem anymore, but with +12 or +20 you'd be fine with 275/60/20.

Maybe with spacers to offset, but not at +27. You'll probably just move the rub from UCA / sway bar to the fender though.

275/60/20 rubs with bilstein max height. Pretty sure 305 wide is gonna rub, even at 3rd setting.

You have to do an alignment either way. Bilstein 5100 or 6112 at anything other than stock height, or spacer, or eibach or anything that changes ride height.

Changing the preload will only affect ride height. With vehicle weight on the shocks, the spring will be at the same level of compression regardless.

Gotcha. So a BDS lift may have more trouble with bumper /fender clearance on -19 offset wheels since there's an additional negative "offset" inherent in the new knuckle. The extra 1" track width is roughly 26mm if I'm doing math right. So a -19 offset on a bracket lift would look like a +7 offset on a knuckle lift? I think? That said, I don't know what kind of suspension clearance issues you may run into with that offset on a 10" wide wheel...

Does the ready lift widen front track too? Just don't wanna overlook a variable.

No clue on ground clearance issues, but you'll want to check out custom offsets with that offset and 35s. I'd be concerned with hitting the bumper and fender that far out with 35s on a knuckle kit. I really like the assault wheel though. As soon as I can convince the wife they're necessary, they're going on my truck.

The brakes should clear down to 17", but with any knuckle lift the smaller the rim, the more limited you get in offsets that will clear the new knuckle.

What wheels? Looks awesome

You're thinking about it wrong. In both scenarios, the starting length should be the full 13" of the non compressed spring. Then both scenarios end with the 7" compressed spring. The difference is the perch height of the bottom of the spring, and where you're temporarily holding the top of the spring (ie, assembled strut). The spring has a linear coefficient, and in both cases is supporting the exact same force. When it reaches the compressed length. The spring does not get stiffer simply because you're starting from a more compressed state... I feel I should clarify... As the two struts are assembled, the 5100s strut assembly is more load on the spring. Once vehicle weight is added, however, they both reach the same compression and are at equal levels of compressive force. The lift height is directly from the modified perch height, not the preload.

I'm not suggesting it should ride like butter, I'm only saying that it isn't the preload. Full coilovers will have similar effects I suspect, but the springs and shocks on those are so much better that you'll more than make up the difference from it.

Let's assume that the relaxed length of the spring is 13", and when on a stock truck, it compresses to 11" in the strut assembly down to 7" with vehicle weight. With bilstein 5100, the strut assembly may only be at 9.15" (11-1.85 raised from the bottom), but the vehicle weight will still only further compress the spring to the exact same 7" with weight. Hence, modified ride height, exact same spring rate. Please note these numbers are arbitrarily chosen.

Still wrong...

Everything you just said is true when the weight of the vehicle is off the strut. The problem is that you're not compressing it further... Once you add the vehicle weight, it becomes the new thing restricting the spring. It's simple physics. Hooke's law states Force (vehicle weight) = k(spring constant) * x (spring displacement). Since the spring didn't change, and the weight didn't change... The displacement could not have changed.

The spring is under the exact same compression as oem length with vehicle weight on it. The spring does not become stiffer or softer just because you started with it a little more compressed. The snap ring changes the full extension of the spring, but does not change compression forces at all.

Preload increases the "pre" load. Doesn't change the total load supported by the spring once vehicle weight is on it. If it did, you'd get less lift and more shit ride.

Yes, spring is more compressed when weight is off the strut, but with the vehicle on the ground it should be the same. The spring constant doesn't change just because you moved a snap ring. Compressed length should be virtually identical. You've added no extra weight.

My point is that the shocks shouldn't feel any different in either of your scenarios. It's the rest of the suspension being stretched that makes it ride rougher (my theory anyway). The shock shouldn't care which notch it is on, the length of the spring with vehicle weight on it is the same in any configuration.

I've had top setting, and currently have stock height setting with my zone 4.5" lift. I couldn't really tell a huge difference to be honest. I think stock setting is a little more comfortable, but hard to say. I think a bigger influence is the control arms / cv axles being strained.