Anything from the '70s is suspect. Quality was all over the place. Core shift is possible on any of this stuff, regardless what it's supposed to be.
for sure, and that holds true for ANY stock block, regardless of year. IMO, 500 HP or more for any stock block is a good rule of thumb for sonic testing.
for sure, and that holds true for ANY stock block, regardless of year. IMO, 500 HP or more for any stock block is a good rule of thumb for sonic testing.