hows it going? my advice is to leave the x heads for the 340 resto crowd they pay the money for them anyway find some 915 sb j heads they out flow um anyway. thats what chrysler switched to in 71 340 anyway. if you get the 360 j heads (915) there exactly the same . except you will have to to have them opened up to 2.02/1.60 same high flowin deal just cheaper. i have seen raw mopar 915 castings the only diff is that chryslers machine shop did the work instead of yours. same part number. except 915 t/a head that ones a little different.as far a magnums too go new is king, and r/t is good ,iron ram heads are best. remember they make 1.6 rockers for the old style too check out kmj performance (cheap) later!!!!