You did not indicate your year of truck in the post above, nor in your Profile-signature.

It looks like you might be referring to 1956 ?

In 1956, Chevrolet trucks came from the factory with baked-on Dupont DULUX synthetic enamel.

Modern single-stage Acrylic enamel would be similar, without or with a hardener.

Single-stage, two-part Urethane enamel would be a more durable "equivalent".

BC/CC might look nice but the base/clear combination is pretty obvious and was not used originally.