340 TA with x heads ? or not

X head, schmecks head. There is NO advantage to the X head what-so-ever performance wise. If it is performance you are after, buy a J head with the 1.88 valves in it, install a 2.02 intake and do a PROPER seat and throat and you will have a better head than anything that came from the factory with a 2.02. The bowl hog crap they do to a head that comes with 2.02 valves from the factory cannot produce the results you can get from doing a correct seat, throat and bowl.