Found a s80 with the style of the T5 cluster, was wondering if it would fit into my V70 and if there was an adapter for it.

 

The only way to swap clusters successfully is to get one from (usually) the exact same model year AND the same part Numbers. On the top of the DIM there's a white label, somewhere on that label you'll see "YZK P/NO 69294-620T" or something like that. Thats the number off my 02 V70, If you can find a cluster matching the "620T" it should technically work.
All the 2001's and 2003 model years I looked at did not have the correct part numbers for my car.

However it will show the mileage of the donor car if it is higher than yours.

Now, taking apart the 2 clusters and swapping gauge faces is a whole other deal, you'll have to pull them apart and take the needles off, Im not sure exactly how to do that, but I think there's write ups around somewhere.