83 KZ1100 Cam cap bolt hole Problems

Alright. I'm about at my wits end and ready to give up on this project because it has fought me tooth and nail every step of the way and yesterday was no different.

Yesterday after timing the cams, and attempting to torque the cam caps down to only 8 ft-lbs (12 ft-lbs as the manual calls for is what stripped my last head). 4 of the holes stripped out on this head as well now. On top of that, I helicoiled one of the stripped out holes and IT won''t even hold 8 ft-lbs...it continues to turn just as the others, I assumed it stripped as well but I have a small kindle of hope that maybe the helicoil itself is just threading farther into the hole...I had to leave the garage for I did not have the patience to investigate any further.

I have used the search function and found a few topics of this problem. I seem to see people suggesting Timeserts and for my already helicoiled hole I may need a Bigsert. I didn't seem to see a whole lot of info though and actually USING the Timesert and whether it was successful or not. I have a few questions...

Judging by videos demonstrating the process, it seems that a problem might be encountered when trying to do the countersink portion. The threads in the hole don't start until about 5 or 6mm or down because the shoulder of the M6x1.0 bolt sits that far into the hole. How is this remedied?

Since I only have the weekends that I can get to the bike, I'm stuck not being able to take my own measurements for this next question. Is there enough meat to actually do this(diameter wise)? It seems like the holes are just so close to the edge where the bearing sits that there won't be enough room especially for a Bigsert, if that is how I am to fix the already helicoiled hole. What about depth? It looks like the Timeserts come in lengths of 8mm, 9.4mm, 12mm, 17mm, and 19mm. Which length should be used?

My bike is a 1983 KZ1100D2 Spectre, the cylinder head is actually an 82'.

I appreciate you taking the time to read this and help me out!

bump, because I really need some insight

Patience and fortitude...
I had a struggle with helicoiled cam-end plug holes, which all stripped out. The only solution I found was the Big-Sert. My fear during the process was that the ends of the casting were going to blow out due to the lack of material there to work with. But using a new tool with extremely sharp cutting edges makes a difference...cut like butter. That curve was a trick though.
All I can suggest is if there is a will...there is a way. And having the attitude that if your repair effort fails, you may just have to get another head.
Regarding the shank length on the bolts, you may be able to cut longer threads on the bolts using a 6mm die, or find suitable replacements for the ones affected. McMaster Carr has a huge selection of nuts and bolts.
www.mcmaster.com/#

Wow that sucks. I have installed hundreds of helicoils and all of them worked great. On my 82 GPz1100 head I stripped one cam cap hole. I then helicoiled all 16 just for peace of mind. I also helicoiled all the cam cap holes and valve cover holes on my KZ650. My experience with Helicoils has been very positive. Are you sure yours was done correctly?