[cstreit]

I would be sure your really REALLY have all the nuts removed... SOmeones that get missed:

There's one in the chain-case area.
The through-bolts beheind the oil-cooler
What about the one under the fan-housing?
Some nuts are on the opposite side of the case...
Are you suure a piston isn't hanging up on a skirt?

I like to use a big rubber mallet. Don't resort to prying.