Hedgehog if you get down to ordering the SRW 350 with the 6.2 consider this. For the limited towing you do you could tow in 5th with the 3.73 and be about the same as the 4.30 gears. Then you have the lower rpm cruising empty.
I have tan F250 6.2 with 4.30 and wish i had went with the 3.73 and towed one gear down.
If the exact same truck has a lower tow rating with the 3.73 I could give a flip. With all those gears to choose from i don't see why the 4.30 ratio converts to higher tow rating, except maybe CYA for the manufacturer. :h