My L is still pretty stock, and I pull a pontoon boat with it. Would a set of 4:10's really make a difference in performance? Would gas mileage (what little there is) suck after the swap? Would it be a waste of money with no other "real" mods ie pulley, chip, cai, nitrous?
Thanks in advance,
Justin

 

Changing to a lower ratio (higher numerically) is a great improvement for towing performance in general. In your case, going from a 3.73 to a 4.10 is a waste of time. There is little difference between the two. A tire height change is more efficient. Usually a .50 or so change is worthwhile. Unlike the 8.8" rear, your 9.75" rear has no available ratio between 4.10 and 4.56 (don't even think about it ). You already have the best towing gear available from Ford in any 97-04 model F-150. Be happy and feel sorry for the other members that have open 3.08s and 3.31s.

 

Alright, thanks for the help. I guess a 4.56 is too much for a daily driver on the highway? I know the answer

 

When the lightning fist came out 99 and 00 the hot set up was the 4.10s and a 2 lbs pulley.STan

 

Seems like most who run lower gears(ie. 4:10) run very well. At what HP level does the 4:10 prove to be too low?
I am thinking the lower gear is great for street fun, and 30" slicks at the track restore taller effective gearing. Any one with experiences with lower gearing care to chime in?

 

The sweet pricey setup would be to go with the 4:10 and a gearvendor overdrive unit.

That way you have the power to tow and double the gears in your tranny because you could have a gear between your existing gears.
Final ratio in overdrive would be aprox. 3:21.
That would be great when your running empty for good mileage.

The smaller tire prolly wouldn't have the right load rating.

I would just live with it stock and stay out of overdrive if your towing big numbers.