I'm not real familiar with small blocks.
Are those port pictures right side up, or upside down?
in other words, are the 340/360 ports taller than 273/318, and slightly wider??
I have a tm7 440 manifold that has had a slug of aluminum added to the top of the port, to work on a max wedge head. Top of the port with added material is fine, bottom of the port, the manifold is razor thin.
