Ported X head pics

X head castings are different than J. I also have a couple sets of virgin 2.02 J heads. I have not measured X head chambers, but you have to mill J heads .040 to get to NHRA minimum blueprint 64.7 cc chambers. J heads came out on 71 360's and were machined for 2.02 at the factory for 340's when they ran out of X heads.