i have an 03 5.4 f150 with 33's on it now.i wanna put new gears but i dont know which ones would work best

 

what gears does it have now?

 

it has the stock ones. i dont know what those are. but a buddy of mine said that if i get bigger gears since i have bigger tires it will help

 

Most likely your truck has 3.55s. Id say stick with the 3.55s, provided that's what you actually have, because you have only increased your stock tire size by one inch, more less.

 

These are the codes for F150s:
19 -- 3.55 non-limited slip
17 -- 3.31 non-limited slip
H9 -- 3.55 limited slip
B6 -- 3.73 limited slip

It should say it somewhere on your driver side door on the sticker

 

yeah a gear change isn't really important unless you move up to 37's. i'm running my stock 3.73 with 33's and its fine, i'm sure 3.55 would be just as good. if its sluggish invest in a programmer, that will help some

 

if you do regear keep in mind are you goin to go bigger later on if so just wait if not keep them stock or go 4.10s for 33s and 4.56s if you want to run 35s

 

are 4.10's really the best way to go with 33's? i know people that say that is more for 35's. I gotta say though i just put 33's on mine and i have 3.73 and my truck is ******* a little more on take offs and up hills

 

4.10's are perfect for 33's thats what im going to be gettin this next week. Youll restore lost power and also get that nice extra oomph and wont really lose any mpg's too. 4.56's are best for 35's to restore power and get a lil extra pull too. Alot of my friends with lifted trucks,35's, and 4.10 gears wish they went with 4.56 instead of 4.10's

 

Here is the formula to calculate what gear will put you close to stock.

Gear x New tire size/old tire size.

3.55x33/31=3.78..