It may well be, as said above that you were in too much of a hurry to put the coolant in!
If it overheated before the gasket was changed, the head COULD be warped, but I would be inclined to find WHY it overheated in the first place - likely causes of overheating:
1) Thermostat failed (if you buy a new one, I would recommend a genuine GM one)
2) Blocked airways through the radiator (inspect)
3) Blocked 'water' passages through the radiator (is the coolant circulating?)
4) Failed 'water' pump -unlikely, but possible.
1,2 and 3 are worth checking before removing the head again.
Regards
If it overheated before the gasket was changed, the head COULD be warped, but I would be inclined to find WHY it overheated in the first place - likely causes of overheating:
1) Thermostat failed (if you buy a new one, I would recommend a genuine GM one)
2) Blocked airways through the radiator (inspect)
3) Blocked 'water' passages through the radiator (is the coolant circulating?)
4) Failed 'water' pump -unlikely, but possible.
1,2 and 3 are worth checking before removing the head again.
Regards
