IWE failures are completely different issue and it doesn't matter what type of shock you run. It's the CV joints you have to worry about when you increase the pre-load on the OEM 2.5 shocks or any other shock you are running.
Running the 3.0 shocks out of the box with factory pre-load settings will be fine. You can even increase the pre-load so the front sits at the mid-perch of the 2.5 shocks and you will be fine.
You won't start to see any CV joint issues until you go with enough pre-load that brings you to what would be top-perch on the 2.5 shock. Even then it won't be much of an issue if you don't go off-road.
I did increase the pre-load on my 3.0's more and more until I got to what is about top-perch and it took about 7 months of hard off-roading before I started seeing CV issues... First issue for was drivers side inner boot failed and I found the outer CV joint was bad. The 2nd was the passenger outside boot failure however the CV joints where good so we just put new inner/outer boots on.
However I do believe it was a combination of things that led to my CV issues including 95k on them with lots of off-road runs. IWE and IWE vacuum hose failures and some front diff issues.
I ended up going with IWE eliminators, a bearing/shim/seal rebuild of the front diff to address some slop in the 3rd member and reducing the pre-load to mid-perch and all is good.
All said my case is on the extreme side my Raptor spends a lot of time in the dirt so I consider some of the issues just maintenance from off-road abuse.
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