K20-Bowtie

I need some guidance. I have a 72 K-20 with a 350 small block, 1406 Edelbrock carburetor and the stock mechanical fuel pump. The engine is running a little rough at idle and the exhaust smells rich. I tested the fuel pressure and it bounces from 8-9 psi (seems high for a mechanical fuel pump). I searched around for guidance on a deadhead fuel pressure regulator and there seems to be conflicting information. Some say a deadhead pressure regulator will damage the mechanical fuel pump. What’s the best option for a regulator or should I go in a different direction?