Also pay attention to rim size, going up the scale everything gets bigger. If you go to a 20 inch rim in a 350 you get bigger brakes also. Then trade the dully for a super single, once you go past 19.5 rim you get more options and bigger brakes.
Then if you need more capacity, take it to a spring shop like I did, Resprung an E350 to an E450. That's my toad.
2006 Fleetwood Bounder 35E Trek pure Trike, electric, 50 mile range, 4700 miles the get everything runner. To be toad list Done, Ford E450 toad. Stay & Play active brakes.
Fulltime since 2018.