Head studs not far enough in!

[paxtec]

Hi,
This place is great for information, it has been invaluable whilst I rebuild my 1987 930 turbo engine, first post here!
I'm using 993 studs and put the first bank in last night following the 135mm height spec and found I can't get 3 out of the 12 in far enough, one is 'stuck' at 147mm.
I've searched and can't find anyone else reporting this problem.
Holes are all clean, no rubbish or liquid in the holes. I'm using the 2 nut method to put them in.
I've thought about heating the base of the stud to loosen the fit but I'm worried that that wreaks the locktite, am I right?
Or get the angle grinder out to shorten them but that offends my mechanical symapathy!!
Many thanks,
Peter

[Flat6pac]

Sounds like you activated the thread lock the factory puts on the stud and stopped in the middle of the install. The factory thread lock is activated with the heat produced on threading.
You need some heat to release it.
I recommend you remove the factory lock and use loctite to install.
Bruce

[Henry Schmidt]

One way to avoid head stud install issues is to clean the case threads with the appropriate forming tap. Be aware that a forming tap is not the same as a thread cutting tap. If you use a thread cutting tap you will most likely end up with over-sided threaded holes. We have had great success with the PD 66- N

[paxtec]

Bruce,
Your advice worked a treat, second bank all in neatly at 135mm, I guess I have to use heat to remove the 3 on the other bank to get them out?
Henry,
I had cleaned the old threads up to the point where the old studs would finger screw into the case, so I guess I didn't need a clean-up tap?
Thanks,
Peter

[RDM]

I put in Henry's studs tonight, after chasing the threads with Henry's tap, and put them in with Loctite. Cleaning the threads with a tap is a must.