Assuming it's a 4 litre, it will depend on the shop rate of the shop you go to, but it is a 6-8 hour job, plus gaskets and machining. This Also assuming the head is not damaged and can be planed. Usually the cause or result of a blown head gasket ,is over heating. Thus other engine damage may have occurred. In my opinion you would be better off locating a good deal on a used engine and replace the engine. If you have trouble locating one, let me know your area and I can locate one near you.