I have a Chevy caprice the heat only gets Luke warm at best. I have replaced the heater core, all hoses, and Radiator it got warmer for about a week then back to Luke warm at best any suggestions.
The heater on my 93 Caprice LS isn’t as hot as my 2000 Blazer but it’s more than adequate. Was the thermostat replaced? If not, that would be my guess.
There may be air in the cooling system.