I was just wondering if a 4:88 gear ratio on a 2007 F-150 2 WD with a 6" inch suspension lift, leveling kit and 3" body lift would be over doing it?

 

Depends on tire size.

 

i would be using 37" tires

 

go for it. ive got 4.88's with 35 and I dont think its too much at all.

 

ok thanks, thats what I am getting then. I want to retain my factory gas mileage and speed.

 

both are going to go down regardless with 9 inches of lift and 37 inch tires. You cant make your truck less aerodynamic and expect the same MPGs.
Will 4.88's help you out significantly in regards to performance and provide you with more enjoyment and drivability out of your 9" lifted truck on 37's?- Definitely

 

have done a lot of research on this and I am aware that it won't be exact but it shouldn't be no more than 1 mpg. I also have Rousch CAI and Dual exhaust...every little bit helps.