The thing is brand new, it rattles like a MF-er when you start it up, when I lay into it I hear some sort of exhaust flutter. Other than those times it's nice and quiet. I read all these post that all the other motors are doing it , so I guess I have to accept it, Right???

 

Not sure on the start up, could be piston slap.
The noise when accelerating is the normal MOD engine sound.

 

I was experiencing a brief ticking from the lifters during cold starts when the temp was below about 32 degrees. I switched to Schaeffer's 5w30 and have never heard it again. The exhaust flutter is a characteristic of the exhaust system on E series vans.