I get it, and I truly don’t mean to rub salt in your wounds. The cam that you were supplied is an offense to what the 340 stands for. A stock replacement cam would have been a better choice, but the fact of the matter is that is in the past.
You will never be happy with that motor until you get a better cam. Nothing you can do, short of forced induction(nitrous,supercharger) will give you the power one would expect from a freshly built 340.
Who supplied the cam? And can we get the part number or actual specs posted? Until you can verify exactly what cam you have, this is all speculation.
