I currently have Mercury Racing 280 tabs on my boat. Does anyone know if the 380 tabs install to the same transom bracket that currently have the 280s? Thank you!

yes direct replacement

Thank you!

Has anyone run the 280 vs 380 on a Donzi Classic 22 Blackhawk, which does have a rocker hull at the transom? The "range" that applies to the 280 is the same as 380, but interested in any opinions regarding these tabs on a Blackhawk

Already 280:s are big on a 22, 380:s can be outright dangerous imo and i doubt you would se any kind of improvement in boat handling.

ran a pair of big tabs, cant recall what they were but they were big, on a 23' Mannerfelt V24 race boat and they about killed us. Took an otherwise manageable mild trip/stuff and turned it into a violent stuff that blew the canopy out (that hurt lol). You'd be better off mounting the 280's flat horizontal if you have the room. We did this on a 23 Avanti and it worked well on all accounts, boat handled sooo much better after that mod.