Check out my car and talk to me about 318/340 swap

think youll need 340 specific motor mounts....other than that its a swap! what size valves in your j heads? if there 2.02/1.60s thay just as good as the X's,.. then its just 22 ci difference if your 318 is stock bore! but it be wayyy cool to have a X headed 340 in that pretty A body you got there!