There are plenty of folks on this site who have "big hp" MRL motors that have under performed at the track (Low MPH for said dyno hp). They tend to not say much when these pissing contests happen. I'm not sure why. I wish they would pipe up more. I can only assume they're happy telling their buddies how much hp they have, but don't actually ever take them to the track.
It's nothing new though. Seems like every small block Chevy at the local cruise-in makes 450 hp. And they've got a dyno graph from the builder to prove it, but the best the can pull at the track is 105mph. LOL