273 cam suggestions

904 v 842 diameter has effect on cam lobe geometry, hence to tech Chrysler does not have to use chevy master grind patterns (olden days but still happens)

you are right would not be surprised if LT1 and chevy brown springs are now re-manufactured offshore like china.. cut production costs as that is happening in au. Or bad quality control/metal blend e.t.c.

for intended purpose LA engines have the ability for 7000rpm using own internals reliably, agree not an advisable spring really with a reasonably stove hot engine