Need input

[brianf40]

My truck is a 2016 Gmc Sierra 2500 hd.  I want to put new rims on it and more but not overly aggressive tires on it.  I was thinking about a 3 inch lift or just a leveling kit on it.  However, my issue is that I pull a fifth wheel with it and do not want to kill my clearance from my bed to the trailer when hitched.  So, a couple questions...

1. If I did nothing to my truck, what is the max size semi aggressive tire I can put on without rubbing? Current stock is 265 70 r17.

 

2. Could I still do a leveling or small lift and be safe with a 5th wheel? 

 

3. What offset will give me about a 1/2inch of the tire sticking out?  

 

Im new to this stuff so plz dumb it down when you reply. ;)  

[Maxsuperdog]

Customoffsets has a large gallery of trucks with all different sizes of wheels and offsets that could give you some idea of what you might want.