First my name is Paul I have a 93 Z28 LT1 I Just picked up the car a few weeks ago. I drove the car back from Illinois and it drove back just fine no overheating my friend that I bought it from said heat worked and all I noticed that the heat wasnt working so when I got the chance I flushed out the radiator but I didnt flush out the heater core after I flushed it out I noticed that the next day when I checked the coolant it was low so I topped it off,then the next day I checked it again it was low I dont notice any coolant leaks but each time I check it its low, I replaced the radiator cap I guess the next step would be replacing the thermostat. any suggestions.....

 

LT1s have a specific fill procedure. If it was not followed, what you are experiencing might happen.

 

I appreciate that info I havent messed with LT1's before