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!
There's more to it than the 22 cu inch difference 318s have lousy heads...low compression etc. Sorry had to chime in saying the only difference is 22 cubes is a misstatement. When talking LA 318 vs 340 stock for stock.
