Old Edelbrock Tarantula Intake Any Good?

Sell em both! Get the RPM Air Gap and a modern Holley. Manifold technology has come a long way since that Tarantula was designed. Hot Rod did a test last year on a 383 using a bunch of different manifolds and the RPM Air Gap outperformed an old Edelbrock single plane by a mile. I don't remember the exact numbers, but the bottom line is that for the street, you can't beat the RPM Air Gap.