Not getting any heat have a 78 l82 Changed the heater valve in line on the heater hoses Air does move from defrost top vents to lower vents put in a new thermostat , and also flushed the system out this eve, was getting good flow of water was a little dirty at first but cleared pretty quick. Heater valve is vacumn operated and new so any advise on what to look for next.

You need to determine whether it is a coolant problem, or a temp control problem. Just CAREFULLY grab the heater hoses. They should get so hot you can't hold them. If you can hold them or if one is noticably cooler than the other, the coolant temp or circulation is the problem. If both hoses are extreamly hot, look under the dash for control problems.

Mike,
A can of Sterno should do nicely.(only kidding)if the problem is in the controls let me know .I have mine apart and have recent knowledge of the sytem in my memory (but only for a little while longer)because of age and lack of brains.
Jules