97 Ford Ranger tire sizes messed up

I just purchased a used 97 ford ranger super cab. I just realized the tires are larger than standard (with speeding ticket). I realize that I can have the speedometer adjusted, is this a good idea or worth the money? Are there any other issues that I should think about with the larger tires on my truck?

The tires that I have now are 235/75R15; I think the factory tires should have been 225/70R14 from the sticker in the door.

how fast were you going. i have found a good web site that will conpare your tire sizes. http://www.miata.net/garage/tirecalc.html . From what you posted you would be going 63 but you speedo would say 60. Also check walmart.com , there you can also check the original tire size.