Overheating after block seal

Once i found oil and coolant was leaking from my headgasket, i decided i'd try to seal it up with some block sealer. I flushed the cooling system really well and used napa's radiator flush before i used the block seal. After i used the block seal, i flushed it all out with water a few times, then i refilled it with the water/anti-freeze mix (50/50). When i took it for a test drive the car was runnning a bit warmer than usual, unless i turned on the heat really hot at full blast... could the block seal have messed up my thermostat? What else could it be?

If you're headgasket was leaking, you should replace it. I don't think block seal's going to do you much good for very long, if at all. I had similar symptoms (without visable leakage) when I blew my headgasket.

gotta let the air outta the system first, until you do it will run hot

gotta let the air outta the system first, until you do it will run hot
if u fill the coolant rite air shouldnt be a problem, i had the same problem and i put a sealer in and all that stuff but it didnt do much, i thought it was the thermostat too but when i pulled it out it was fine so in the end i just replaced the head gasket and it hasent been a problem since. quick question, when u start your car in the morning does it run on 3 cylinders ore just really rough for the first mile or so?

It sounds to me like you know what you need to do. Change the damn head gasket. You went to all this work already, why didn't you just fix the head gasket in the first place?

Its simple, just make sure that you remove the head with the engine at TDC and replace it that way. Its also a good time to check the wear on you piston/cylinders.