That's an M90. Looks like a GenV too. I'd say he's not out of line for that price by looking at pictures.... but then I read the description. Why would they bother rebuilding it? Even better question is why is he selling it for scrap yard prices if he has all that money in a rebuild? Dude's lying or hiding something.https://milwaukee.craigslist.org/pts/d/pewaukee-3800sc-engine/7482958073.html
Dunno about 700, I think it's an M62 equipped engine?