Wade,
I just cleaned out my block on my engine stand. I just pulled out all the plugs and kept shooting my garden hose's spray gun back and forth and up ang down, while spinning the engine and poking a long coat hanger, bent as a hook, to reach in and break up the gunk, sand and casting pieces laying in there for years. I spent HOURS getting EVERYTHING out. It'll probably run very cooler than it ever has in it's life.
If yours is still in the car, only pull the ones that you can reinstall or you'll be pulling your engine out to hammer them back in. (I only use the rubber ones in an emergency)