I have a sport 250, I have been watching 280s for some time and I have been in a few. very nice budget minded boats. there was a guy locally that turned his 330s into 496 strokers in his 280 running mid 80s. very roomy nice boats, someday when I think I need twins the 280 is at the top of my list. the 330s are the only downfall but like I mentioned you can turn them to stroker motors for a reasonable amount. could also build them up with l29 heads on the cheap, those peanut port heads are the worst part of them

Adding a blade is about 150 RPM and dropping pitch from Mirage 23's to Bravo 22's is about 200 RPM
Box stock that is and dependant on application specifics.
Anyway, they work really well on my Nova