After a reman cyl head and new rings for my 1.6na, and intermediate headaches described here in other threads, I put the original 11 mm head bolts back, torqued 'em up in 3 stages per the Bentley, and fired up the engine to warm it up for the first re-torque. When I did, I got a pop and no more torque out of one of the bolts. Backed it out, bolt is fine so threads probably sheared off in the block. I had put a dab of Permatex anti-seize compound on each bolt, and am now concerned that even using the Bentley numbers (50,70,90 Nm) I effectively over-torqued the block threads due to the lower friction from the anti-seize(?).
I know the 11's are known to be weak, and I've likely abused mine. Am wondering if I can save the block by time-serting the threads and using ARP's or Raceware's studs along with whatever lube they supply or recommend. Opinions? Am I wasting my time? If this were a horse I'd be calling the glue factory...