is it possible to fit the R series gauge cluster into a 2001 s80 without having to do major interior mods??

 

At minimum expect a trip to the dealership for a software change, but I don't think a V70R gauge cluster will be a direct swap either.

 

The cluster it self will probalby fit right in and the connector is also similer but you can not put software into a cluster (dim) that has all ready been programed that will not work. the only possible option you would have is getting a new one from the dealer and seeing if they could do it. but is it worth trying for probably around 1500