You will need some....
Front
====
YES!
Certainly a fair bit at BOTTOM back of front arches...
Remove lower ARCH LINER ( OR CUT IT, I DID)..Cut away some of metal .. hammer back etc.. ..re-cover with arch liner......
...nothing structural under there. Small 'not required' pressed metal cross brace.. mines gone..no issues.
Pics in my gallery
AND.. some of lower lip of front cladding.. bit by bit till you do enough IMO!
It'll rub more on sharp turns.
Back
===
Shouldnt need any, though your wheels will rotate fwd a bit given lift.
A few of us with 35's have fitted adjustable rear links in order to center wheels again...
...plus lengthened the rear drive shaft to restore spline depth in yolk.
Hope this helps.. holla if ya need more.
Jo