I would not do it. Your owners manual will give all the specs as to towing. The 6.0 is a good engine for pulling a boat...a 15500K 5er is a different story. Over time you will probably kill the engine and trans and your fuel mileage will suck...5-6 MPG towing. The $6K upgrade for the Duramax/Allison combo will over time pay you back for the money spent. I get 11.8 average fuel mileage towing and that is double what you will get. IMHO, a 15500K trailer needs a 1tn and at least a SRW for safe towing. BTW, all the specs change greatly with the D/A combo over the gas engine.