Okay; I flushed the the entire system. I disconnected both heater hoses and flushed both directions. I then poured simple green into the heater core and let set overnight. Then flushed again both directions. I then added coolant system conditioner and antifreeze.
Guess what; it's working.
Warm air on both sides of the cab. This is a great forum, alot of good information posted. Thanks again guys.