2017 f250 towing fifth wheel

the tires are F (127Q) rated and and say 3860 @ 80psi

Not to sound mean but you don't have enough truck for a 5th wheel toy hauler. Even the short ones will be outside the payload rating of your F-250. You'd be better off with a bumper pull toy hauler.

I know the hitch should weigh 287 lbs. I guess I need to put truck on a scale full of fuel and family? If I'm understanding that correctly.

Welcome to the forum and congrats on the new camper. One of the first things you'll learn on here is that there's two crowds of people.

One that thinks if you go one pound over any of your weight ratings your truck will fall apart and you'll be sued before you can get to the first stop light. They will tell you you're crazy for looking at 5th wheels with a 250 and that you're a fool for not buying a dually.

Then there are those of us that know current class 2 trucks (F250) are a very capable truck and built almost entirely identical to a F350 single wheel. This crowd will care much more about the RAWR and tire ratings on a truck and not the "payload' rating. Your truck will gross out at 10K like every other 250/2500 regardless of make, engine or options. This 10k limit is an arbitrary number established by the government.

Personally I would tell you to keep your shopping to units with no more than 3000lb LOADED pin weight. I just purchased a 13000lb toyhauler with roughly 2800ln pin weight and my truck squatted exaclty one inch.

If you shop strictly on your available payload per door sticker you'll be all but limited to large travel trailers and very small 5th wheels.

Welcome to the forum Keith!

Most FW/TH size will be determined by how much weight the truck can carry. Most of the pin wt will be carried on the rear axle. If you know the scaled wt of rear axle, with truck loaded, full fuel, passengers, weight of hitch, then you just need to look at RAWR/tire max load, to see how much is left for pin weight of FW.

example: truck loaded rear axle scaled weight 3300...truck RAWR 6,500, you would have 3,200 lbs left for loaded to go TH pin wt.

Jerry

What ever you get keep the GVWR under about 12,000 pounds. Otherwise you will be overloading your truck. Length is immaterial weight is.