hi my brother has a 340 which runs the mopar performance aluminium closed chamber heads and when the motor was built he had to use like a 100 thou gasket because the pistons hung out like 40 thou or whatever they hang out on a stock 340,my cousin is now building a 360 and has come across a set of the open chamber eddys,just an aluminum version of a j or x,my question isshould my brother swap him for the eddys so he has the correct 340 style open chambers and then he can go back to a normal gasket and my cousin get the closed chambers for his 360 with a zero deck height,basically as we all know there the same head basically both made by edelbrock and flow the same,would the 340 be better with the original style opens or should he leave it as is,car goes pretty good now runs like a 12.2 in a 72 challenger???
