Thank you challenger 340 for bringing this potential problem to my attention,my new world block was prep by Ohio crank.I also saw ARP nuts and thought i had the best studs also,but as pointed out who knows what we have.I have checked these studs with thread mics and the major dia and pitch dia was perfect that is on the long studs,that was not the case with the 2 shorter #5 position these where streched as you had found .the pitch dia and major dia are way under tolerance this happend in the area of thread that did not enter the block threads.This indicates to me that this is a very bad thing.As i said before ARP only way to go.