Need advice if safe for my pickup to pull a heavy 5th wheel

If you can figure out the pin weight, then that will tell you what you need to see on the door sticker. Most of the newer 3500/350 SRW will easily pull more weight than your trailer. The problem is the amount they can carry. Make sure the Payload is higher than your pin weight, fuel, people, dogs, firewood and anything else you may decide to haul in the truck.