Hello all- I am doing a gear change from 3.55 to 4.10. I will be towing a 2003 Salem 30ft. TT loaded approx. 7,400#. I wanted the gear change to get me into a better torque range.
the truck 99 f150 4x4 5.4L tow package with K&N fipk, superchips micro tuner, and a cat back 1 in 2 out exhaust.
Should I expect much of a change I just want to be able to go down the road at around 60, or with a head wind and not feel like I am beating up the truck.

thanks.
ps reason for the 4.10 and not 4.56 or4.88 is this will still be a daily driver.

 

it will make a good difference. make sure you keep OD off and a bigger trans cooler is a must. preferably one with an e-fan.

 

Can I just buy another cooler and run it inline with the stock cooler. Or ditch the stock cooler and get one with an e-fan???

 

You should be about 500 RPM higher than the original gearing for a given commuter speed or about 10MPH slower at the the original RPM. The extra gearing will feel like the truck is pulling easier off the line. A gear swap 2-steps lower (3.55-3.73-4.10) will be notable off the line. Once moving you really won't notice any difference because towing at speed is more a factory of horse-power and torque than gearing. (unless you radically change your gear ratios) You get in a head wind and it will slow you down just about as fast as the higher gears.

The 4.56 or 4.88 would definately handle head wind and hills better being a more radical gear change but you could also expect major reduction in fuel economy.
I know you probably know this but since you have a 4x4 you need to change both axles gears so you will not tear up the t-case in 4-wheel drive.

 

If you have anything larger than stock 32" tires, go for 4.56 gears.

 

[QUOTE=The 4.56 or 4.88 would definately handle head wind and hills better being a more radical gear change but you could also expect major reduction in fuel economy.[/QUOTE]

i recently did a gear swap from 3.55 to 4.56 with 32" tires. best thing i ever did. my mpg have increased while towing and for everyday driving, so i don't think you should expect a "major reduction in fuel economy" unless you drive alot at interstate speeds while empty.