Personally I wouldn't tow 14k fiver with 3/4 ton. Way over payload rating. That would be a 2800 pin which will leave you about 200 lbs before adding hitch, gear, passengers, etc.
I have 6.0 and 4:10 axle on 1 ton srw. My fiver gvwr is 12,400. This set up works well for me for weekend towing and one long trip per year. There is no way I would be comfortable pulling anything heavier with a gasser though.
You will want to stick with 12k gvwr fiver or less for your 3/4 ton truck. Or you will be finding a reason to get a 2014 1 ton.
