Just wanted to share my thoughts on this.
Helped my shop mate assemble his vintage race L16 motor today.
Ever felt a head bolt stretch? Neither had I before today!
While doing the last 10 ft/lbs torque on the bolts (280ZX turbo head bolts) to a total of 60 ft/lbs; on the third last bolt I felt the dreaded ease on the tension... oh s**t! We took the bolts out, sacrificed that head gasket - but to be honest we could not see a difference in the bolt that went soft. It would have been good to have a mic'd before and after length on that bolt. But we didn't take any chances, and we discarded the whole set of bolts at that point.
It's an O ringed block, closed chamber head, and since new pistons just went in on this "freshen up", we didn't want to take chances. Luckily I had another head gasket in my collection of bits at the shop (thanks Hainz!!), and at my work I had an ARP head stud kit that was to be used in my new motor for the Bronze - Paul will get this for now and replace it for me later. At least we got the motor assembled. It's only the second time I've used the ARP head studs, and I can say that I sure do like the "feel" of them being tightened, at least compared to the stock head bolts that I had done an hour and a half earlier in the day. The actual torquing felt more consistently smooth. This may have to do with the moly lube on the thread and under the bearing surface of the ARP nut. The factory bolts were oiled with engine oil – I guess it depends on if you want to believe the ARP “propaganda” that comes with the bolt kits. In any way, the ARP studs definitely felt better being torque to 60 ft/lbs (recommended torque by ARP)
At least tomorrow I can get back to playing with the cutting and grinding on Rob cage, now that the motor is buttoned up and nicely sealed ina bag
I just couldn't understand why my shop mate didn't want the extra lapping compound in the air while he was assembling 
Byron
