Currently have 02' FX-4 4x4 5.4L automatic. Has LS 3:55 rear gears...how much difference (seat of the pants) does it make to go to 3:73 or 4:11 rear gears in acceleration and how much would my highway RPM increase? Cost? Is it worth it??


THanks in advance.

 

I can't compare an F150 with 3.55 to one with 3.73, but I can say that my '03 Expy with 3.73 feels much better than the '02 F150 with 3.55 did. Even though the Expy is heavier, it feels like it would out run the F150. I would like to know how the F150 would have felt with 3.73.

 

The SOP on 4.11 would be "faster off the line" than the 3.73s, and the 3.73s faster than the 3.55s. Keep in mind that you are gaining more low end, not top end. Your highway RPM will be considerably higher with the 4.11s, and therefore lower mpg and additional engine strain. You'll also get whine from the higher gears, don't think you won't notice it-you will.

As for cost, 4X4 means twice the cost of 4X2 because you can't just do one diff, and you will need to have the speedo adjusted as well.

I don't see many people who need to change their gears (to increase towing ability, or overcome large tires for example), but there seem to be a lot of folks who want to.

If you want to spend $750+ to be the fastest guy in first gear then knock yourself out.

 

Thanks for the reply. Not worth the cost.