Racecarl, two things about stretchy head bolts. Some head bolts are intended to be stretched as this guarantees that the bolts all hold with the same force. I have not seen this type of bolt used on anything older than about 1980. Second, if you have an old set of bolts that stretch while being tightened, this is indicative of major overheating of the bolts at some time and annealling/softening of the steel. Throw them in the junk bucket to be used as pins or something later in life. Glad to hear you are making progress, can't have Tony enjoying all the fun rebuilding motors! smile