I just got a 6" Rough Country lift and 35" tires on 18" wheels, and was wondering if regearing is required? or recommended?

 

It's never required per say but at 35" those tires will reduce your rpms by anywhere from 7-15% depending on original tire size. Regearing to pick that back up will help maintain the performance and most importantly keep from putting all the extra stress on your tranny from lugging around the truck.

 

not required if your ok with how your barge gets up to speed.