For the 2011 series 2, the 3ltr V6 and 6ltr V8 are E85 compatible while the 3.6ltr V6 is not...
For e85, the tank, fuel lines, vapour lines and seals need to be alcohol compatible. Whether all these components are standardised as e85 capable as a matter of production/parts consolidation, I don’t know. You also need a flex fuel sensor and wiring to the ECU. And the ECU needs to be able to accept the flex fuel sensor wire and have appropriate map that caters for the % alcohol reported by the flex fuel sensor... (I’ve read the 3.6ltr V6 ECU is not capable of handling the flex fuel sensor input but I cam5 say whether this is correct or not so it needs to be looked into).
So you'd need to check the 3ltr and/or 6ltr parts list against the 3.6ltr parts list and if the parts are the same then they are e85 compatible.
I‘ve also heard that the piston rings are different in flex fuel engines but no idea if this is actually true... but the injectors must be able to cope with the higher fuel flow volume needed for e85 so thats one thing would need updating.
As to a kit... haven’t heard or looked for one as I don’t have an LLT...
You may want to read
this thread and the links within for more background...