Thumpr cam crap

If the cam is installed properly including preload, it's not the cam. Unless it has a flat lobe. They idle fine and just as you want.

There is a different fly in the ointment. Drilling the primaries is a bad deal and a crutch to cover other issues.

Vaccum leak, needles not held down at idle (lighter springs) are a couple of the issues that may be causing problems.