^^^ I agree. I am always in favor of diagnosis and checks before throwing parts at something. OP did say they installed a different cam though...the .488 lift cam.is that the one that steered him wrong? I have the SUMMIT .444 in my 340 and it runs pretty good. I did run the .444 in a 318 also with good results in a street engine, stock heads and springs, it pulled ok to a point then kinda leveled out...