I just shipped a fully enclosed crate with 302 + Fulton visor, extra valve cover, and no flywheel or bell housing and it was 702 lbs. tony, I'd put the motor at around 575-600 lbs.
Here is the same motor with chain, big truck flywheel, pressure plate and bell, along with external oil filter and 12 quart oil pan. By the time you strip all the big truck stuff off, it is quite a bit lighter. It is being lifted here just off the motor stand.
