My son and I just got some 16x7 wheels for his 87 4runner. The 4runner had 15" wheels with 31x10.50 tires. We would like to get 265/75 16 tires for his 4runner. I don't know what the original tire size was but do I need to think about changing gear ratios. The gears are original, I think they are 4.10. Is there a problem perhaps with the computer if the gears are not changed? If we need to change the gears what ratio? Is there one brand of gear that are better then other? Thanks.