[RichardJ]

I think the 3.55 you mentioned would be a better choice than 3.08 for a stick with small engine.
Automatics can generally handle taller gears and that is what some of these guys have in mind with that recommendation.
The chart below is from an Off-road web site so you can take it for just a comparison reference only.
They put 3.07 gears at the bottom of the useful range and even then only with a 28" tire which is a pretty small truck tire.

Personally I think even for KS, your 250 would struggle with hills, head winds and much of a load with 3.07 gears.

I swapped the 4.56 gears for 3.54 gears in my truck. The most noticeable bang-for-the-buck on my truck next to AC. 75 on the hwy and can handle most hills without straining.