I've run .040" stainless O-rings in an iron head GMC for years with .015" sticking out and never had a problem sealing the compression. The only problem was with the copper gaskets around the water passeges. I've even used the same combo on stock gaskets and did not have a problem. Now using a Best head gasket. This is with 14-1. Our 12 port aluminum head has .050" o-ring stainless wire with a .065" reciever groove in the block. I buy the wire from Mc Master-Carr.
If you still have problems an old racer running a blown Chrysler to me to O-ring the block and head at different diameters and o-ring both with stainless(no reciever grooves)and run copper gaskets. If I ever have any more problems it's what I will do.
Good Luck.
PS: more info on the BBQ annealing...My BBQ will get to 600+ degrees on the front temp guage. How hot and how long. I have been doing in with a rose bud and hi heat bricks....
