those rims look NASTY... and no you wont have a problem pulling trailer with 35's this boat weighs in around 15k and I'm running 35's and no worry of the tires rubbing with it sagging.... but do keep in mind I am only on 18s not 20s but as far as clearing in the rear when squatted NO PROBLEM
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Travis 
06 2500 Megacab 4x4 gets a bath twice a week