If you are looking for lug nuts for the 16" Lionshead Steel Dual Wheel - 16" x 6" - 8 on 6-1/2 - 4.75" Pilot - Silver Item # LHHA420 that you referenced then you need the 5/8" Flange Wheel Nut # 95188. For a standard 16" wheel like the Dexstar Silver Modular Trailer Wheel # AM20760 you would need a 60 degree coned lug nut like part # CE11050.
For a vehicle you may need different lug nuts as trailers can sometimes use different lug nut sizes than passenger vehicles. view full answer...
For your 2016 Ford F-550 that has the bed with recessed gooseneck I recommend the Demco Recon Gooseneck-to-5th Wheel Trailer Hitch Adapter # DM8550046. This hitch does require that the top of your gooseneck ball must be within 13/16" of the top of the bed. It is rated for 21,000lbs towing and 5,250lbs of tongue weight. Your recessed opening must be at least 8" long x 5" wide for this hitch to fit into that opening.
I recommend using a Lube Plate # C16722 with any 5th wheel to reduce the... view full answer...