[mechanickeith]

That manifold is a 61 model year manifold. It is a dual plane with one primary & secondary carb barrels going to 2 cylinders the other 2 carb barrels go to the other 2 cylinders. The 62-63 4 barrel manifold is a single plane with all 4 barrels of the carb going to all cylinders. The 61 manifold will give more torque than the 62-63 manifold but the 62-63 makes more horse power. Here is a pic of a 62-63 manifold so you can compare. The Rochester 4GC carb is not the best to use on the 4 cyls. Try & find a Carter AFB in the 450 cfm range. Much better fuel milage & performance