I reckon This is one of those topics that is unlikely to result in a clear consensus
The first time I built my “basket” engine it blew a head gasket when it done more than 500 miles, and over 10 rides. I fixed it (using the same solid gasket, re annealed) and worked out that the root cause was that my (nearly new) torque wrench was not accurate. It was over reading by over 40% so the bolts were WAY under tightened, but interestingly it held together for quite a while, and probably only blew because being the bolts loosened off even further, I guess because they were so loose to start with, with some ending up little more than finger tight, so I guess In my experience the applied torque is not super critical, provided they stay done up!
After fixing that and a few more miles it dawned on me that I’d used the same wrench on the big ends
so (after a trip to the pub) I stripped the engine to re torque those.
Anyway, the point is that people’s experiences will differ depending on the accuracy of torque wrenches, flatness of surfaces, type of gasket, how many heat cycles or miles before being re torqued, oiled or non oiled bolts, whether the head is iron or ally, washer hardness, etc etc
Regardless of that, like prior posts I agree the “gold standard” would be to re-torque (with calibrated wrench) all the head bolts after (insert your own number, maybe 10?) heat cycles or (insert your number, maybe 500?) miles which ever comes first. Unless I experience an unexpected blown gasket I’ll not be doing it though!
