Well i found out the hard way that my speedometer is quite abit off this weekend driving back from Missouri. I had my cruise control at 77 and i was clocked at 87 according to the cop, thank god he only gave me a warning, but how to i go about adjusting my speedometer to the correct speed after putting on my 315's

 

See if there is a speedometer shop around, they can calibrate it for you, or companies like Superlift make speedo recalibrating units.

 

I see you still have a 12v so it's not as easy as plugging in a computer chip. There was a post here some time ago about the same issue and it said you need to replace the vss gear. Do a search, you'll find it. vssman was the author of the solution.

If you find a shop that sells these gears please let me know. I have contacted 4 or 5 plus the dealer and can't find anyone that has them.

Good luck

 

The dealer sells the speedo gears! They have a selection of them, but not for 315's...

 

try this http://www.superlift.com/

 

www.chromewheel.com

 

You probably can get pretty close with a vss gear change. You need to know the overall tire height and then you can calculate the number of teeth you need comparing it to what you have. If that's too much trouble, I've found Rickson wheels to be very helpfull. Prices are pretty much in line with the dealer too. As for tips on installing it, look up one of my previous posts a couple of weeks ago on this same topic.