okay so your saying the x and j heads are the exact same and one doesnt have any benefits over the other? i live in the chicago area andi dont plan on driving it in cold weather so this shouldnt be an issue??
No, that's what you inferred not what I conveyed. I said they were the same as far as compression. All X heads....that I know of anyway came with 2.02 intake valves. Only some of the J heads came with the 2.02 valves. If you compare X and J heads both with 2.02 valves, again rumblefish nailed it, in that case, they are both the same. Does that help?