Does anyone know what the protrusions or "nubs" are on the Edelbrock 573 manifold that I circled in the photo. They are on the 553 and Edelbrock's 4 and 2X4 manifolds also. They don't seem to serve any purpose.



At some point, someone in the past machined them off of my 553, maybe at the same time it was "ported".





Thanks to Timmy's Y-Block Page for the picture




"The Master Cylinder"

Enjoying life at the beach in SOCAL