Camshaft question

Right, so far no idea what the mystery cam is, or idle vacuum..

Here is the Mopar 340 Cam specs that I use as a baseline to compare other cam specs to.
It's a good basic cam, with good performance and a decent idle.

Rpm Range: Idle to 5000 rpm.
114* Lobe Centers (less valve overlap)

As camshaft selections move up the rpm scale, the valve overlap increases giving the choppy idle.
(as the cam centerline numbers decrease, the valve overlap increases)

Mopar340Cam.png