Thanks for words of wisdom. My 400 motor (YT Block, 300 HP, 10.75 C.R.), auto trans (PX code, turbo 400) and 3.08 axle ratio are stock - but previous owner installed an Edelbrock (Performer Pontiac) manifold and Holly 650 CFM 4 barrel carb.

Do you have suggestions on cam and exhaust performance upgrades that are bullet proof that you are willing to share? I'd consider changing the manifold and carb as well but not sure it is worth the extra money.

My 68 is my daily driver. I drive 15 miles roundtrip each day and want to keep the car a daily driver - but boost the performance a bit so I can show my wealthier friends in their new Teslas what a real car is!