I’m not sure how this is the 340’s fault?
Did you actually VERIFY that you have that much fuel pressure? I’m doubting you do. That needs to be cleared up first.
Yes I completley agree. Haven't you ever gotten tired of an old girlfriend though? She was nice at first but then you just got tired of those personality quirks. That's where I am at with this motor.
The fact that it will just run bad for no explanation. I don't know if there is a fuel issue or not. All I can see is that the gauge shows 12.5 psi.
The most confusing part of all is that it doesn't run bad until it is warmed up and been running a while. Motor starts losing power. Bogs down and doesn't want to idle.
If when you killed the original cam you didn’t pull the engine and complete disassemble and clean it, then that’s why this time it’s dead. You can’t kill a lobe and think the filter will get all the crap going through the engine. Most likely, the filter plugged rather quickly and then just bypassed all the oil right into the engine.
So address the fuel pressure issue first, then pull the engine, clean it up, replace the parts you killed and put it back together.
The fact that it’s a 340 has zero relevance to anything except what you superimpose on it.