Overheating wowes that make no sense - help!!!

My 69 bee with a 383 had alot of over heating issues. Turned out to be sediment in the bottom of the block. Didn't seem like much when I flushed it out but it was enough to restrict flow. I just pulled the hoses and thermostat and flushed it with a garden hose from the top and bottom. Problem solved for me.