Have a 89 1500 p/u with a 350, air shocks. Truck is in pristine condition with only 108,000 miles. It was used to pull a car inside a car trailer. I now have a 4000# horse trailer and 2 horses. Guessing total weight will be about 6200#'s. I need an educated answer as to whether or not this truck is ok to pull the trailer/horses.