I have had a six pack on many of my 440 cars for over 25 years now. I love them. They do require vacuum. Depending on your camshaft, timing, etc, they are great. If your RB is produces adequate vacuum levels at idle, leave them stock and just put it on and enjoy...
Here's the six pack I just fired up yesterday as a matter of fact.. It's on my 440 that's totally OEM inside.
