Will be a nice rig Alan.
Switching to 4:30 gears and Load range "E" tires really improved towing experience with my F-150. I run 33" tires, but with stock tire size, 4:10 gears should be 'bout right.
As in comment above, if your F-150 does not have one, get as big a tranny cooler as you can and switch over to Redline synthetic transmission fluid.
Here are f-150 axle codes - you can find your 2 digit code on your door sticker:
19 – 3.55 Non-LS
18 – 3.08 Non-LS
H9 – 3.55 LS
B6 – 3.73 LS