No problems on a 79 series (or many other LC) models, with the change to 265/75s. Only a very small increase in overall height and rolling radius. So changes to mpg and Speedo reading are minimal.
Depending on what look you're going for, you might even get away with 285/75r16s - looks ultra cool imho but will have a bigger impact on Speedo and fuel economy etc. not to mention any potential rubbing issues.
We need some pics! ;-)