79 Delta 88 overheating/dieselling

My Delta has recently started overheating when I get up to temp on the road. I am also not getting any heat out of the heater/defroster obviously the coolant is not circulating. To make matters worse, it is dieselling for a few seconds when I shut it off but only when it overheats.

typical water pump failure empeller rusted off blades also change thermostat.and recommend a belt change.also flush radiator off car method check for leaks.
check belt tensioner recommend replacement also.I have been their done that.91chevy lumina 3.3 and 91 olds 3.8 delta 88.refill 70% green coolant 30%water.add a sealer in case you have a head gasket seeping.check and replace hoses even if they look good can not afford replacing coolant twice.heater hoses a must reguard less. your right their you might getter her done once through. winter comming i do not like working in cold.