New in crate powerhead? What does that mean? I have a hard time believing it is a brand new from Mercury, 280hp factory powerhead. For $2K, that is unheard of. It should run at least $6,500.
I don't know what the issues were with the early 2.5L Merc's, but I know there were some bugs in them. You may want to try to post the same message over at www.screamandfly.com
There are more O/B guru's over there. Good Luck