72 350 rocket overheated because the transmission wouldnt shift from 3 to 4 on the highway the shop said they have to put a new themostat housing on before they can test to see if is blown head gasket but i dont think it is it just ran rough and when i changed the oil it wasnt milky and my spark plugs didnt have coolent on them so i just dont want them to charge me 1200 to rebuild if thats not the case

 

Some years ago I ran a tired 70 cutlass at the local poor mans race track. I ran it in 2nd and we hit the passing gear down the straights .You would have to run it alot harder then that to blow the head gaskets,most likley!