Hello, anyone know if the stock 20" 275/55r/20 mounts under bed for spare tire set up. Looking to mount it in place of the 18" spare tire. Also planning on dual exhaust out rear under bumper in future, any thoughts of problems relating to larger spare tire under bed. 2015 Supercrew. Did a search but nothing showing.

 

The wheel diameter won't matter one bit, so since the tire is the same width and diameter you won't have a problem.