I put a class 3 hitch on my Explorer because I regularly haul either a heavy boat, or a heavy trailer. It didn't require me to remove the bumper.

If you are just hauling a DB, you might be able to get away with just the stock ball. I towed my 14ft runabout for 4 years without a problem behind my '84 Toyota. Try it first to see how it tracks at all speeds

My hitch set-up is from Draw-tite, but I had a dealer install it.