calvin

hey guys I have a 97 f150 4x4 I got new 285/75/16 tires on it with 3:55 gears. I used a 18 tooth speedo gear and this combo works great but now I want more power down low so I am going to install 4:10s does anybody know off hand what speedo gear to use and what would be roughly my new ratio with 285s and 4:10s. I think with 3:55s and 285s I have a ratio of about 3:27 now and would anyone know what the ford part number for the new speedo gear I would need be. Also anybody running this combo 4:10s/285s/4.6l if so how does it work? thanks

Ty

get a edge tuner, you will have more power, and be able to figure in for the larger tires without having to change the speedo gear.

calvin

anybody know what speedo gear to run with 285s and 4:10s ?

88blkf150

i kno when u put 4.10s in a mustang athey say to change the spedo gear but the one ur supposed to change it too isnt the right one the one they tellu to use is actualy the one for 3.73s

calvin

this is a little different because it is not only the gears throwing you off it is the big tires two that change your ratio also.....If they would of told me I could use what on learn on my truck when I was in school I would of listened in math class.....maybe.....lol....lol.....Calvin

calvin

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thequaz

If you take your truck to ford they will reprogram your computer for the new gears and tires. Andyou would not have to install anything or mess with the math