correct speed with 22.5's on f350

[lews930]

I just installed some 22.5's with 255/80's and realized I didint do all my homework.

I measured my rpm and speed in 5th gear with stock 235/85/16 tires. I then ran the 22.5' and did the same thing but realized the speedo is now wrong. I am running 4.10 gears

anyone know the correct speed? i dont have a gps to measure

thanks

 

[WUnderwood]

try this:
http://www.superlift.com/accessories/truspeed.asp

 

[Mo Smoke]

Hey Lewis I have one of those for sale if interested