good luck on the drilling of the rest of the bolt hole, i would not rust the hole repair stuff on a head bolt , it works great on parts that do not have a lot of stress on them , it is a mix of powered metal and high grade epoxy, take alook at their matrix chart and for the size of the head bolt , it doesn,t appear to have enough strength to trust for a long period , not counting the amount of work to repair if it doesn,t hold, if worst comes to worst let me know later i have 12-15 of those blocks on hand most all of the time that could be rebuilt , JERRY

Thanks.

Any idea how much the head bolts actually stretch when tightened?

I managed to get it tapped what looks to be deep enough - .18" beyond what will be required to have the bolt tight against the head with a head gasket in between. I should have at least .15" for bolt stretch and I can't imagine even those spindly little bolts stretching .1" with ~ 48 ft/lbs of torque on them.

I could probably tap it a little further down but I'm afraid that every time I run and tighten the tap that I am removing a small part of the threads, even if it is a small amount.

Well I finally had sucess!!! The broke bolt is out!!!! Wasn't that hard. I drilled in the center of the broke stud, starting with a small bit then working my way up to a size that was big and deep enough for me to get the reverse bit in it. I did have to find a socket that would fit it cause it was to deep to use to the tap. I used a socket instead and once it grabbed it came out nice and easy. The threads are fine as well!!

I can email you a pic of the "tool" i used if you want. Just P.M. me with your email. Sent you a P.M. as well.

Tomorrow I can tell you how much my stock head bolts stretched ((16 new head bolts came in for the tune of $100)

TO TELL YOU THE TRUTH I HAVE NEVER MEASURE HEAD BOLT STRETCH, BUT BY GOING HOW ROD BOLTS STRETCH, WHICH IS MINIMUL, I WOULD GUESS MAYBE .005 THOU, .150 IS A BUNCH, OF STRETCH EVEN THOUGH THE ARE KINDA LONG , I WILL TAKE A LOOK LATER TODAY AT A NEW BOLT AND A USED ONE AND SEE IF I CAN MEASURE ONE AND GET BACK TO YOU ON THIS ONE , HOWEVER IT WOULD ONLY BE AN APPROXIMATE READING AS YOU KNOW THE BOLT WOULD NOW BE IN A RELAXED STATE , JERRY

Got the truck back together. What a project it has been. Hydrolock, bent rod, broken head bolt. Back together but with a water leak which is the o ring in the middle of the valley then try to start only to find that the new timing belt is faulty (a tiny bit too long). Installed a Gates belt and it fired right up and seems as good as, well as good as can be expected for a "free" truck with 200k miles.

Thanks so much to all you guys for the support.

HEY THAS GREAT, I FINALLY GOT TO MEASURE THE HD BOLTS , I COULD NOT FIND MY MIKE THAT NOT WHERE IT WAS SUPPOSSED TO BE , BUT ANYWAY , I MEASURED A USED BOLT AND A NEW ONE AND THE NEW ONE WAS 7/10 THOUSANDS SHORTER THAN THE USED ONE , HAVE NO IDEA HOW LONG THE USED ONE HAD BEEN USED , I JUST TOOK IT OUT OF A CYL HEAD AND MEASURED IT , EVIDENTLY NOT A LOT OF STREATCH . JERRY