Overheating wowes that make no sense - help!!!

If the lower hose collapses, it MOST OFTEN is not a hose problem, but rather a restriction, like a plugged radiator. Someone mentioned you might have "block fill."

Friend of mine once had some heads exchanged, and the "new" heads had loose crap in 'em. Plugged the bottom of the rad. You could rev the engine--a 383--and it would suck the hose so hard it would BEND THE BOTTOM OF THE RADIATOR TANK