How do you replace a blown head gasket on a 1975 Buick 350 4 barrel?

first you need to remove the valve covers and the intake manifold and the upper raditior hose also the distribuitor after you take all that stuff of you should see the large bolts that holds the head to the block take them off and remove ALL the old gasket off the head and block and put it pack together by tightining the heads from the middle out same with the intake

hi there,

whoever posted this answer is caorrect, but i'd like to add on what has already been said. Be sure to drain the cooling system of all the coolant. this can be done by removing the lower radiator hose. alos, whenver you work on the enigine, be sure to disconnect the negative battery cable, as this helps preent accidents whernver service is being done.