I like my 2009 F150 with 3:55 LS, feels about right for mix city/hwy/towing. Thinking of ordering a 2011 and doing a 2-2.5" Leveling kit with 305 tires. What gear ratio should I get, if I were to get 3:73 and then increase the tire size what equivalent gear ratio would I be at? Thanks.

 

305 is how wide we need to know the exact tire size

 

yeah... 305 what?

 

305/55/20 so just over 33"

 

Leave the stock 3.73 gears id say

 

I ran the calculation, going from 31.6" diameter to 33.19" diameter on 3.73's would be equivalent of 3.55's. However I just found on another thread that I cant get an Ecoboost Platinum with 3.73's (w/o Max Trailer Tow Package) so with 3.55's it would be like having 3.38's

 

If you go with 305/55/20 you can keep your 3.55's as well.. its not going to make a massive difference until you get to 35's and bigger. So either way 3.55 with your current truck or you can do it with 3.73 on a 2011.

 

I'm gonna be in the same fix, running 305x55x20's with 3.55 gear's. Should be OK with a 33" tire. A programmer should help too.

 

I think I am going to do the 305's and just see if it TRULY bothers me with 3.55 gears.

 

i hated mine with 3:55's. I got a fx4 this time just for the 3:73's. Of course i went from a 06 to a 10, so im sure the tranny has alittle to do with the difference. i also had an 2005 fx4 with 35's and aftermarkets and it also had more giddy up then my lariat with 3:55's. Thats only my opinion. I had no aftermarket engine stuff either, just wheels and tires. So there you go