I am going to buy an 02 4x4 tacoma this weekend and I have a set of brand new 31x10.5R15's that I don't want to give up on a trade in. Will these fit on a stock 4x4 tacoma? Is the speedo reporgrammable or do I have to replace the speedo gear?

 

Yes, if you get one with 15" wheels on it.

 

The 31x10.5x15 is amost the exact same outside diameter as the stock 265/70/16, so the speedometer will be correct. The only problem would be the caliper hitting the rims if the 02 Tacoma originally had 16" rims. This can be solved by using a Dremel or grinder to remove a very small amount of metal from the end of the caliper.
If the Tacoma came with 15" rims, I quess it would use the 31x10.5x15 tires.

 

my 01 had 15;rims with 255's and i switched them out to 31 10's with no problem you have no problem with the calipers at all