Hey guys, I am brand new to 4x4 trucks with lifts and all. I am picked up a 93 f150 with a 3 inch lift and 33/12.5 tires. The truck has a 351. The power seems fine and low speeds but very sluggish accelerating at 55mph and above. I've read that you need to change the gears when using bigger tires. I was wondering what gears do I have and what gears should I get. I would still like to use the truck on the highway and not kill me in gas. Do I have to change both front and rear gears? Thanks alot in advance.
Brian

 

 

A 3.55 gear will be fine, thats what I'm running with my 33's. It's probably the fact that the 351 made less or about 200hp and needs to be upgraded there for highway passing. I know what you mean, having driven my dad's 92 302 with 3.55's 2wd. The engines are crying for more hp's. I think starting with headers and a good exhaust will help get things moving, or at least sound like it's going faster.

Yes to changing front and rears, almost positive they have to be the same ratio. It seems to make sense to me anyways.

 

thanks alot. I found in the owners manual that by the door code I have 3.55 gears. I guess if I were to put in 4.10's it would kill me in gas milage?

 

Gearing change is really significant if you go with 35" tires or larger... There is not much loss with 33" tires... Remember that changing out the gears can be very expensive...

 

Oh yah, gas mileage would tank. You have a good setup, just need to get that engine working better. Gen 1 Lightning intake and heads? That should get you near 250 hp alone, maybe a cam swap too. Sorry, I like to spend others money for them, it's easier than spending my own!!!

 

Nice lookin truck.....noob lol i had a extended cab with 33s once i loved it till i blew it up
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agreed. im running 3.08 gears with 33x11.50x16 tires with no real power loss problems and i have a 4.2L haha