90 acclaim///head gasket problem??

When the car is running and i have the radiator cap off, i am getting fluid shooting out the radiator, it seems tohappen on certain strokes. and there is a little white smoke every so often, the thermostat is pulled , and i have back flushed the system. now i have to tell ya, the car was driven 3 miles on almost no fluid cuz of a hole in the hose. I am hoping the heads were not warped. now how hard is it to get to the head gasket??
Also i run the 4spd auto trannie with the overdrive unplugged, otherwise it doesnt shift outof first, any help will be appreciated