Regarding the copper Tom mentions. The copper is a masking that is applied before induction hardening. It allows the lobes to be hardened for long wear while the shaft remains ductile for easier straightening and resistance to breakage.
It is typical for 8620 and a few other alloys that are oven heated as part of the hardening process.
You will note it here at 4.37 on this video:
https://www.enginelabs.com/news/vide...ith-comp-cams/
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/
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5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE