Short hop the 280 probably quicker. I had a 2.4 carbed motor on an XR 2002 and it would run 107-108 all day any day. It might surprise the XB2002 on top. I know they sure feel more secure. Secure is usually fast.
Never will forget a 1998 XR2001 I raced for a couple of years. For the time it had a pretty hot 2.5 Drag motor on it. Tight heads, block stuffed, good reeds, light flywheel, etc. It was down for a rebuild and I stuck a 2.4 carbed Bridgeport on the boat with a 150 hp nitrous set up. It jerked the batteries and fuel cell out of the floor. I had a video of it on the initial hit and the entire boat was out of the water on launch and you could see the prop. Great feeling till the juice ran out. Sitting in front of one of the V8 OMC's with 650 hp has to be a hoot.