Just an old dinosaur of a head from the 60's and 70's.... 2.02" intake and 1.60" exhaust.... They were good in their day I guess, but there are soooooooo many new heads out now, both cast iron and aluminum that will outperform them right out of the box... If you're doing a "numbers correct" restoration and this is what your car came with then find a set. If you want to go fast, get the modern stuff!!!! These heads are old.....going to take a bunch of money to redo the guides, port and flow work, stainless valves, screw in studs and on and on whereas the good new ones come with all the necessary parts installed.....