I tried a search and could not find a definte answer, only a thread pretty much asking the same thing. If anyone has tried to put 2j cams in a 1j head, please let me know. Also would a 1j benifit at all from stock(us spec)2j cams? In the US it's easy to get 2j aftermarket stuff, but very hard to get 1j stuff. I would go with aftermarket 2j cams, but would like to see if stock ones would be an improvment. Thanks.