Cutting the bump stop will certainly give a tad more travel. But will also prematurely destroy your front shock.
You should consider (if it aint done) level the front end, and adding in a pair of longer shocks, The superlift 85331 kit is a good bet http://www.summitracing.com/int/part...aised/3-000-in
orrrr not... doesnt matter if you have 4.0 kings. your bump stop is there to stop the shock from bottoming out and if you have factory from susp (not counting shocks) then the bump stop needs to stay where it is