340 Stock Camshaft

Which I understand is good for a lower compression motor but the idle will be very rough and low vacuum
No, I don't think so. This cam has alot of overlap which bleeds the compresion off and the lower numeric centerline also lends to this problem. At higher RPM's, this problem goes away because the engines efficeintce (SP!) goes up and a ramming effect takes place.

The wider 114 helps retain compresion at low RPM.

I have (For sale as well) the MoPar 288/ .499 oval track Hyd. cam. No tappets. It is a 108 to be installed at 106.