Mitch is dead on here.
I had a F150 nearly identical to his except mine was a 2wd. I had a 31 ft TT that weighed about 7000 lbs loaded. I pulled it all over the hills of Tennessee. I was under all my Axle weights but about 50 lbs over GVWR.
I remember going up a 7% grade in second gear. Never into first, truck slowed down, but it was not struggling. It pulled great.
Regretted getting rid of that truck. I "upgraded" to a Dually because we wanted to put a golf cart in the bead and we got a crew cab as a bonus.
I took a lot of time to make sure that the F150 was set up right, and after getting behind the wheel of the dually the change was ... not significant. My F350 had a V10, so the RPM range was about the same for the motor.
If you feel the 5.4 is struggling at 3400-4500 ish rpm's... its not.. its doing its thing. It will run at that RPM all day long.
Thanks!
Jeremiah
TV-2022 Silverado 2WD
TT - Zinger 270BH
WD Hitch- HaulMaster 1,000 lb Round Bar
Dual Friction bar sway control
Itโs Kind of Fun to do the Impossible
~Walt Disney~