it was right when i had the 32"s on it but it now off when i put the stock tire on it

 

I would first try and find out what gears ya got in there.

 

sounds like a pull off the cover and count the gears type of day

 

Well that's one way to do it lol

 

Yea... the hardest way...

Once you figure out what gears you are putting in it, and what tires are going on it, use this chart to determine what size gear to put in the speedometer sensor, on your transmission tailhousing.

http://www.high-impact.net/DodgeSpeedoGears.htm