14 ply 16" is no problem, I can have a set on the dock Tuesday with one phone call. 

The height should be a problem with the 17.5's.  I don't feel like doing the math but I can't see how a 215/75R17.5 could work out to be much taller then a 235/85R16. 

Okay, I'm not as lazy as I thought, I did the math for you.  The 215/75-17.5 should be 767mm tall and the 235/85R16 should be 805 mm tall.  A 7.50R16 is slightly shorter then the 235, probably pretty close to the 17.5