What is so different from the 80 series and the 70 series. I bought a Gck 60 - 23 bx grass catcher . When I bought it I didn't own a Kubota. I made it fit onto a Massey Gc 2300 . The frame was just a bit narrower then the Kubotas plus the PTO shaft on the massey was lower down. I made it work on the massey. I then bought a Kubota BX 2350 and made the grass catcher fit on it. I now have a BX 2370-1 and use it on it now. With a little imagination etc: and fabricating you shouldn't have to much problems making it work on a BX 2380.
Is there that much different from the 70 series to the 80 series rear frame and pto location. To be honest I can't see that there's going to be that much different in the rear frames or how its going to mount.