Gen4 leaning after lift kit install - what to look for?

First thing is to check the rear springs you removed. If they are both the same, (as they would be on a LHD gen3 so very likely the saem on a gen4), then you will get a lean from fitting odd springs. In which case I'd contact the supplier and see if they can supply a matching pair of rear springs e.g. 2 labelled as drivers side.
If the original springs are an odd pair then try swapping your lift kit springs around so the one labelled drivers is on the right hand side.

Each of the pairs seems to be the same length.
I am just not sure of which were in the front and which on the rear.
 

I hope a more experienced Jimny enthusiast can give me an opinion on my thoughts.

As of right now I still believe that the lift kit has incorrect parts but the brand/supplier insists that it is not, and I will give them the benefit of doubt as maybe in a heavily loaded situation it is.

I was thinking on changing the springs to the H&R +40mm to fix the lean and possibly the rough ride quality.  But I was informed that the shock absorbers/dampers also play a role here.  
So maybe in the end I will have to get the Bilstein shocks to replace the green man ones. 

 

The longer pair will be from the front. Looking at the 2 shorter springs, do they have the same number of turns and is the wire thickness the same? If so then the lean is 100% being caused by the fact you've fitted different length springs on the back.

A RHD lift kit is, by the very fact it exists, going to be incorrect for a LHD Jimny. The car should sit level when unloaded. Loading will obviously affect how it sits, but that's not the route to correcting un-level suspension.

Given the supplier isn't offering to help and you are unhappy with the harsh ride (springs and shocks can both cause this) I would simply return them. H&R and Bilstein are both amongst the best in their respective fields. I would choose them over any 4x4/Off-road brand.

wrote:

Is measuring the top of the tires against the flares a correct method to get data about this?.
 

The most accurate way to measure "lift" is to use the lower edge of the rim as your reference - put a tape on the lower edge, run the tape past the center of the hub and read the tape where it intersects with the wheel arch or in this case flare.  This method avoids errors caused by "hard to quantify" variables such as tire size, wear and inflation, but is affected by rim diameter.

Ideally a "before lift" measurement should have been taken so that there was a base line to compare to, and what many people don't realize is that the front suspension heights impact the rear suspension heights - a droop in the front right corner will tip the rear left corner upwards (and vice versa) - you need to look at all four corners.

One of my 4WDs was a Mitsubishi that I acquired with very tired front springs, I struggled with dynamically varying negative camber until I realised it was caused by sagging springs which were then replaced with OEM parts, I later fitted 50mm lift coils (Dobinsons) and ended up in a scenario very similar to that of the thread starter, the illusion that one rear corner had more lift than the other, the rear springs were handed, and correctly fitted.

I don't advocate mixing & matching suspension components, you might get away with it if you're using OE replacement parts, but if you're looking at some sort of upgrade part, it's very easy to get things mismatched - shock/strut damping needs to be matched to the spring rate.  I have not used ironman products (they are not available where I am), everything I've read about them suggests that they are stiffer/harsher than most users care for, the dobinsons I've used have a higher spring rate (stiffer) that I am comfortable with and dobinsons did not offer a matching shock for the Mitsubishi, so I ended up with a harsh, underdamped ride, Old Man Emu is what I will be looking at for my Jimny, I've had them on a GV for the last decade or so, and have been quite happy there.

Old Man Emu usually offers several springs for any given vehicle, the difference being in the "free length", the spring rates are usually the same, and they will usually have shocks/struts valved to work with their springs, and whatever bump stops or extensions that are needed.

My apologies on the late reply, I got flooded with tasks at work. 

I will try the measurements on the already lifted Jimny and report back. 

In the meantime as I said I am eyeballing springs to solve the lean and the bouncy/rough ride. 

The Ironman rear springs is the model SUZ010B (RHD), which to my understanding is creating the lean and its higher rate to +200Kg makes it a rough ride. 
The front springs are the SUZ009B (works for both LHD/RHD) with +80Kg (to support steel bumper and winch),  my car is completely stock in the front and with plans on modifying in the future with an smaller/stylish bumper and maybe an snorke.  

I was thinking on these options to try to solve the 2 issues. 

The cheapest: 
Get the JimnyBits 2” (50mm) rear springs only and keep the Ironman front springs and the front/rear shocks
www.jimnybits.com/2-jimny-lift-springs.html

The change all springs but loose 1 centimeter of lift option:
Get the JimnyStyle H&R +40mm springs, replace all IronMan springs and keep the Ironman Shocks and loose 1CM of lift in the process(I kind of like the 5CM look, but not sure if this would be noticeable)
streettracklife.com/collections/jimny-su..._fid=8a0a89856&_ss=c

The polish option:
Do some research on the X-Shock-Dakar lift kit solution regarding its stiffness and get the full lift kit, replace all springs and try both IronMan and X-Shock-Dakar shocks to see what is better. 
www.xshockdakar.com/en/shop/details/107/...kit-jimny-jb-74.html