My '95 F150 4X4 5.0 AOD is an absolute stone! I made the mistake of ordering it with the 5.0 and stock gear ratio (3.37:1 I think). It downshifts out of overdrive constantly when I encounter the slightest grade. The gas mileage is hideous! hideous!!! No matter how I drive it.
I've been considering a switch to 3.91:1's, a catback exhaust and a K&N filter element.If I'm going to live with 10-12 MPG (the sticker said 14-19), I might as well have a little throttle response.
Anyone have any experience with this combo? How do I correct the speedo and odometer after the gear change(s)? Any good manuals available for installing the gears and setting up the pattern and backlash?
You probably have the 3:31 gear ratio, and your tranny is more than likely a slightly improved AOD with a wider gear ratio named the 4r70W. I'm encountering the same problem with my truck, only its amplified by the fact that i'm turning 35's. I would say that a 4:10 Ratio should do pretty well for us. Good luck and let me know what you decide to do.
oh..and by the way....the speedometer will automaticly correct for the gear swap, a tire size it will not correct for. Summit Racing has a good video on gear set up available. I belive Richmond gear produced it.
What size tires are you running? I loved the gear swap I did to 4.56 when I was running 36 " tall tsl's. Since I went to the 39.5's, I probably should change to 5.14. I also still get 11 to 12 mpg depending on how I drive. good luck.
I've got 3.55s in my 96 F-150 5 speed and it is doggy with the 31 x 10.5 x 15 tires on it. If you are going to stay with your current tire size the 3.73 ratio will work well with a good performance economy balance. If you will tow alot or haul heavy loads and maybe do bigger tires someday 4.11's would be a great choice. I have a 91 Suburban 1/2 ton 350 CID that I am running 33 x 12.50 x 15 tires on, when I got it there were 3.73s in it and was terrible on the highway and in town, now I am running 4.56s and I increased mileage from 12 to 16 mpg and the performance step up was awesome.