M661 bar studs too short - nut/collar only half threaded

[mikereiche]

I picked up a used ms661 that had a stripped bar stud.  I heli-coiled the hole and replaced the stud.  The replacement stud is 3mm shorter than the original, having only 8 threads versus 11.  ( it seems all 1138-664-2400 only have 8 threads ) .   Combine that with nut/collar only being threaded in the top half (why, Stihl?) and the nut was only catching the first three threads which eventually stripped.  I replaced the stud and  heli-coiled the full length of the nut/collar and am back in business. 

My question is - is there a longer bar stud that would work? Maybe an ms880 bar stud with wide part machined down?

[dave86]

This one has 11 threads

https://www.chainsawpartsworld.com/product/stihl-ms661-chain-bar-stud/