The manifold is exactly like an Edelbrock that I have. It even has the little raised things on the left side runners for machining. It also has the provision in the back drivers side for the 55 Chevy water temp probe. That was a 55 only deal. I have a pic of my manifold on the car in 57. The carbs are absolutely 55 Chevy carbs. They are the only ones with the little hats for bowl vents. The whole thing is probably mid to late 50's.