For your 2008 KZ Spree 27 RLSE 5th wheel trailer, the Ultra-Fab 2" Trailer Hitch Receiver for Trailer Frames # UF35-946403 is a great weld on option that will give you a 3,500 lb towing capacity and a 350 lb tongue weight.
For a bolt-on option, I recommend the Curt Adjustable Width Trailer Hitch Receiver for RVs, 22" to 72" Wide # C13704 which is rated for trailers up to 3,500 lbs and 350 lb tongue weight. You can alternatively use the Curt # 13703 which uses a different style bracket... view full answer...