got an 02 f150 fx4 with 3.55 gears. I intend on getting a 6" lift and 35's later but want to upgrade the rear end first. I'm going to put 4.56's in but what diam. is my rear end and should i do the same in the front. what kind of tire roast should i expect from the dramatic change until i get the lift and tires? will i get better hp worse gas mileage? or am i just a retard. i have nunchuck skills and am trained with a bowstaf. thanks

 

First off, what motor do you have?

4.6 = 8.8 Rear
5.4= 9.75 Rear

You should be able to broil your factory rear tires with 4:56's, and I'd imagine you'd spin your 35's pretty well too (depending on what motor you have).

 

5.4 motor. should i regear the front also. will i gain top end, acceleration, neither, both or what else?

 

Both axles on a 4x4 should have the same gearing at all times.

 

You'll be smoking your rear's alright if you don't swap both axles with the same gears and drive your truck in 4 WD. Not a very smart thing to do.