I have the traditional 280 k-planes. Is there any advantage to going up to the 380s? Other than looking cool. I think I could just insert new tabs into my existing connectors? Thanks.

Yes they fit, and they work twice as good as the 280's.
I upgraded last year and I love them. Watch out for clearance issues with the prop.

Do you have a twin engine boat? I'm concerned about the clearance from the props.

No, I don't. You might find your ok. I had to limit my hydraulic steering rams with some internal spacers. It was well worth it.

Unless you're running staggered twins, I think you'll have to cut the 380's and do so slightly different whether you're running a Bravo or Speed Master setup. They'll help get you up on plane and can help stabilize the boat at high speeds if you tickle them down. I bought mine from Diamond Performance on this site who cut them to clear my SSMV's. I've got a really high 'x' dimension and they really help me get on plane with a full load of fuel. For what it's worth...