How come they did not gasket match the 302 heads to the stock 318 intake manifold gasket ?
That is the very first thing you do when establishing smooth port flow. Can't see the forest for the tree.
There is a big step there to remove with any manifold that is bolted up to the 318 302 heads to avoid turbulence.
More important than any internal port work that they are trying to achieve.
Proper port match as follows:
View attachment 1716031144
Needs gasket matching as pictured below on the stock 302 heads:
View attachment 1716031145For some reason they have not done this important step???