My car over-heated and cooked

[BillionPa]

after you determine that there is no block or head damage, replace the headgasket, valve cover gaskets, radiator hoses.

pressure wash the radiator to get rid of all the crap, change the oil, fill with coolant.

then after 500 miles, flush the coolant and oil one more time.

[632 Regal]

ditto, the only thing you will accomplish by tightening the head bolts at this time is a bunch of broken studs in the block.