hey everyone, im new around here and have a couple of questions regarding my diff. gearing.
ive got a 2001 f-250 5.4 v8

i recently went up in tire size to 315's, up from 295's.
my question is, where can i get some info on where i can get new gearing for my differential....front and rear, and how much can i expect to spend.

i know it used to get around 14 mpg, now its at a fluctuating 9-10, plus theres a lot less punch to the acceleration.

any help would be greatly appreciated.
also, where is the cheapest place to get a k&n

 

I've delt with Randys Ring and Pinion for gears. http://www.ringpinion.com/

 

Spectre
It's been a while since I learned this but I believe the following to be accurate. Someone please post if the following is not correct.
Not knowing the specifics of the changes you made in tire size I will assume that you have gone up in width from a 295 to a 315 without a change in profile. As I recall, a 315/75 tire would be taller than a 295/75. The number after the width/ is the profile which means that the sidewall would be 75 percent as wide as the footprint. If there was a width increase as well as a profile increase it should make your speedometer/odometer slow showing you less miles traveled between pit stops. It would also make your gearing taller there by reducing acceleration.

Good luck

tom

 

Check with Marty or Kevin at the link below they are located down in McAllen
http://trucktoyzperformance.com/

 

Did you correct the speedo? Your mileage differance may be due to that.