I couldn't find the formula in the search column. I have a 97 F150 4x4 4.6 with 265/75/R16's and the 4.56's are going in next week. I need this gear real soon, and if I can't find one with the right number where can I order one?

 

4lo.com has soome good tools for what you are going to do. I would start there.

 

THe VSS gear is a ford specific part for the 4r70w trans. I don't want to drive it with the shift pattern that far off after the ring and pinion change. And thats this tuesday.

 

Every Ford dealer I've talked to trying to find a VSS gear for either my 285/75/16s or my 315/75/16s don't have anything. From what I've been able to gather from them all that dealerships will carry are the stock sizes (ie, 235/70/16, 255/70/16, and 265/70/17). To find a gear like what you want you're most likely going to have to look in the aftermarket. I know there are companies out there who make VSS gears (I have a website but can't remember what it is anymore). So you've decided to go with 4.56 gears and only staying with 265/75/16s? IMO, thats still way overkill, even for 33" tall tires let alone 31s.

 

You can get the speedo gear through Steeda. The biggest gear is a 23 tooth one. Your speedometer will still be off around 5%.

 

Wow. 4.56:1 gears is pretty low. I am planning to go with 4.10:1 gears in mine. I am running 285/75/16's on a 16X10 wheel. With the 285/75/16 tires, 3.73:1 will put me ratio wise about where I was factory so I want to go a little lower than that. Unless you are planning on towing all the time or planning on just offroading all the time, I would go with a higher gear especialy with the tires you have. I think you will be unsatisified with the gears. I think they will be way too low. Yea you will have power out the yang but you will lose alot of fuel milage. You will be running about 2500 rpms at 70mph. Factory you should be running about 74mph at 2000 rpms. 4.56:1 would be good if you were running planning on running 38 inch tires, but not the size you are running. Here is a good site for 4.10:1 gears if you decide to change your mind... http://www.gefracing.com/Merchant2/m...ry_Code=46REAR
Hope this helps,
-Landon