If you look at the GVWR of Ford's 2013 F150s, they range from 6450# to 8200#. The 126" wheel base, 3.7L V6 4x2 is 6450#. With >145" wheel base and the 5L V8 or Ecoboost with HD Payload option, you can get up to 8200#.
Looking at a single wheelbase/engine (157" 4x4 Ecoboost): the GVWR ranges from a base 7350#, to 7700# with the MaxTow option, to 8200# with the HD Payload option. AFAIK the MaxTow adds additional engine and tranny cooling (+ other options for trailer towing). HD Payload adds a 7 lug wheels/axle (+increased rear GAWR), heavy duty suspension and LT metric tries.
AFAIK all these trucks have the same braking system.
