From my personal experience (2001 DII W/3" RTE) and several other friends (3-4)(OME & RTE) that have/had 3? lifts on DII?s they seem to be very receptive to the 3? lift.
My personal opinion is that the DII comes with a double cardan front drive shaft (the part that many people replace to get rid of vibes on the DI) and this makes the difference. Additionally if you search on here I am sure you will find very few people complaining about vibes on the DII that are related to lift. When a post comes up about vibes on a DII most of the time it is the front u joints (in the drive shaft) that are the cause and not the lift, Although the lift can cause the front non-serviceable joint to wear faster.
Mainly I think it is peoples perception that if the DI had soooo many issues with vibes the DII must also, but that is just not true in my opinion.
With that said?.
You never know, I may have just been lucky and you could get vibes
But if you try it and you get vibes it is easy enough to reinstall your old springs.