Steve ,
I tried all kinds of bolt torques and bolt manufacturers in the '60s. I will say it was "MY" lack of experience that caused my gasket failures. Too much compression , timing , and lack of fuel quality ( even though we had 100 octane leaded gas). As I look back on my approach , I was lifting the head off of the block by detonation that I caused. My "seat of the pants dyno" was out of calibration and I was out of control. The good thing is the early failures showed me the limits and strengths of most of the engine parts. I went as far as 100 ft lbs tq on the heads with no improvement on sealing. I also O ringed the heads which helped some and finally tried solid copper head gaskets as a last resort.
"Now" I use 10 additional ft lbs on the upper row of head bolts as "I" believe the intake manifold torque does play a role against upper head bolt torque. With "modern" head gaskets and 50 years of tuning experience , I no longer lose head gaskets.
Randy