Engine shakes BADLY!!
I agree with 67Dart that motor mounts do not cause an engine to shake. I've started engines (albeit they were stock engines) sitting on the ground with absolutely nothing holding them down and they didn't shake. Either it's just the big cam and things aren't tuned right or it wasn't balanced right.
BTW: that Lunati 60405 is a pretty darn healthy cam for a 340. You probably didn't change the idle much by switching to it. If you wanted a mellower idle you should have went with a cam about 2 sizes smaller like the 60403
Post a new video and we'll listen to it again. And this time post an under hood shot of the engine itself idling. We can tell a lot more if we actually see and hear it