You are telling him how do do the job. Why not do it yourself. I don't know how you can have any faith in him.

I agree with carfixer007 ^^^^^^^

You have shown the ability to learn, the ability to observe, report, learn about a foreign subject, research, put a lot of complex concepts together that are not your specialty, and come up with a somewhat clear picture. Your shortcoming appears to be loyalty to this "mechanic". I bet with some of the right tools, a good service manual, and a little advice from someone experienced, you could do this job better than this "mechanic" has been able to so far.

"mechanic": It leaked because the brand new head that I installed may be warped"

Machine shop: No, it'* fine

"mechanic": <crickets>

. . . right?

Great news!

I feel the need to point out that I have been consistent in stating that the "mechanic" needs to be qualified and either know the correct procedure and/or have the correct procedure available from the correct documentation, know how to follow the procedure, then actually follow it properly. I've given lots of clear instructions that have been often missed, ignored, questioned, and/or misinterpreted in this thread. You have "given him Cathedralclub'* instruction part as a guide", and that'* probably good, however, this depends on which part of my instructions you gave and how he interprets it. Since I advised (several times) that the whole project be taken elsewhere, and it sounds like it has not been taken elsewhere, I am concerned that:

1. the "mechanic" will get the wrong part of my instructions, an incomplete part of my instructions, and/or instruction(*) without surrounding context
2. the "mechanic" will perform these and/or other instructions on repeatedly damaged parts
3. the "mechanic" will, yet again, give you back a broken car and simply say "I followed the instructions you gave me from that CatharsisClaw and now your engine is broken. It is all the fault of the instructions from that CathodeCrawl that you gave me, good luck sucker!"

For this repair, this "mechanic" should:

1. not take advice that doesn't already come from the official GM procedure for this repair
2. take the disassembled block and head to a machine shop, pay them to certify that both are not warped, cracked, and that all screw holes have good threads that are undamaged, and give you the paperwork proving that these have been done
3. Take all of the parts, including new replacement parts where necessary, to a real mechanic to be put together properly (perhaps the same machine shop?)

I don't think he will want to take the block out of the vehicle to go have tested. He just wants to do this job once more and if it works great ..that is what he is thinking.

I have asked for threads to be cleaned of all including all oil and dry before assembly.
Head and block to be checked with straight edge
Head to be torqued using no lubricant and torqued according to the manual (new gasket and bolts used)
New bolts used for valve timing sprockets.
Timing chain tensioner to be inactivated before installation and then activated as per instructions.

So the checks at machine shop will not get done

I'm crossing my fingers for you!

You cross your fingers. I crossed my eyes three days ago and haven't seen straight since.

I didn't exclude other crossed things nor their duration.

It sure makes typing difficult though!

LOL....

This may sound obvious but will check. If the instructions on head bolt are tighten to 22 ft lbs then 155 degrees, for the degrees, can you do say 90 and 65 if there is something in the way or should you make space and do the 155 in one forward motion or doesn't make any difference.
Thanks

Do them at 22 then do the 155 in a steady motion without stops. Technically if you stop early you need to start over with a new bolt.

I mentioned this to the mechanic and he insists that he can do 90 then 65 as long as it is done on the same bolt before moving on to the next bolt in the sequence.
I have asked what is the harm in doing the 155 in one motion but haven't yet received a response.