your mechanics are fixing the "effect" of an underlying problem. Did the first mechanic install a paper headgasket rather than an original metal one?
Does it pass a pressure test?
How was overheat determined?
Is system on coolant or plain water? If on water was condition of block and head ok when opened?
Bolts tightened correctly?
Waterpump and other plumbing in good shape?
There are lots ot parameters to look at, not just gasket farigh, nawee fit kardo, dract fan lagao 4 relay ke saath, 8 naali radiator bhi lagalo aur mazaar ke dum ka paani bhi daaldo