Were these shields an option or installed at just a few plants? I have the correct 702 heads and bought the shields from Corvette Central, They bolt to a small boss on head with a quarter inch bolt.

They weren't used on Chevelles, just Corvettes. The 702 heads have the mounting bosses for the shields because the 702s were also used on 390HP 427s in Corvettes.
Bruce

I wasnt sure but that clarifies things up a lot. I will be sending heat shields back. Thanks for the quick response!