Come'on blackdiamond.... cut me a little slack. If you are inferring that I'd would pull a 16 trailer at 80 MPH with my truck and that's "crazy", you may be right, but I most likely will just keep the freeway speeds between 70 and 75 and between 60 and 65 on 2 lane and windy hilly roads. I live in AZ and if you ever get down here and drive on the 17 or 10 freeways on a Friday afternoon during the summer, I assume you'll be shocked when you get blown passed by guys pulling boats, jet skis, travel trailers, 5th wheels, and ATCs when you are going 75 MPH!!l Is it crazy? Yeah it can be. So going 80 MPH pulling a trailer where you live may be an oxymoron, but around here it seems to be the S.O.P.!! 
MUAHAHAHAHHA or a 1998 Kenworth W900L with 600 hp and 2200 pounds of torque after leaving Commiefornia and hell bent on making Texas in three hours.
At this point, I'm not even sure this engine and truck will be OK to pull a 16 or17' fiberglass Casita trailer??
I think it will do just fine. as long as Lucy doesnt add a rock from every single place you stop
I've pulled trailers with all 5 of my trucks a good number of times and I'm very aware of the dynamics involved. In fact, I believe my XtraCab will pull a 16' travel trailer, albeit slowly, I just know that the braking part of controlling it may be dicey, it ain't got the torque of a Dodge diesel. The weight of the trailer tends to "push" the back end around on the truck on deceleration and braking... and that can be safety issue.
I have pulled a 21' Ski boat on a dual axle tandem trailer with my '85 shortbed 22R, with zero problems, I just didn't go over 65 MPH, and took extra care to avoid having to brake heavily.
I think you'll pull that ok.
No I mean I dont have an office program on this computer I cant open your spreadsheet.
