I would be a bit nervous as well about a blown engine, what the previous owner was doing to get it that way. Either way, check carfax for any accidents. No matter what they tell you, even if they say it was a bumper, tell them you don't give a shit, because when you go to sell the next person won't believe you.

Then go through the service history. If all looks good, and engine is really new, go for it.