im going from a 235 tires to a 31 inch tall tire and i want my speedo to be dead on like it is now how can i recalibrate and i cant afford to regear. i have a 94 4.0 and 5 speed

 

Change your speedo cable drive gear.

 

how can i do that and where can i get one

 

Ford sells them, at least they used to.
http://www.therangerstation.com/tech...peedogear.html

 

what one would i need?

 

You would need to know the old and new tire specs, either diameter or revs/mile. You can get those from the tire manufacturer's website. Then find out what speedometer gear you have now and do the ratio calculation to see what you need.

BTW, "31" tires are usually 30.4~30.7" tall, not 31" as logic would imply.

 

ok thanks alot man