i have a 98 f150 i bought thats allready lifted and has 35's it doesnt seem sluggish and its acctualy pretty peppy but it still sucks on mpg. But my question is is there anyway to tell what gears it has without opening the diff. The axle code says its a 3.55 but i feel that it may have been regeared anyway to tell?

 

hay try this link it will help you guess put in the numbers you know then guess what rear ratio you have but first make sure your speedometer is right have someone drive next to you at a pre determined speed and see if you match that speed http://www.ringpinion.com/content/calculators/RPM.asp