Largest tire size that can go on a 3/4 ton 8 lug 16 x 6.5 wheel?

[CMNTMXR81]

I'm sure this has been asked before.  I went through some 20 pages looking but didn't see anything.

 

2003, 2500/2500HD 16x6.5, 8-165.1 bolt patterned wheel...  What is the largest size you can go?

 

Originals are 245/75/16.  Previous owner of my truck put 265/75/16's on.  I could've swore, back in the day on my '02 2500HD with these same wheels, I put 285/75/16.  Even looking through my maintenance records, It says that size tire...  So I wanted to do that same size again and now all the tire places are wigging out because of the goofy 6.5" rim and the bead difference on it vs. a non half size wheel.

 

I really wanted to go with that size.  It gives the extra width and another half inch or so of lift to help with clearance on my plow.  So to get similiar lift, I now have to get tires AND bigger wheels.