A generalization as to the sound/radical idle, is that the tighter the lobe separation, and the resulting larger overlap, the more radical a given cam will sound. Yours is on a 112° ls, the thumper is on a 107° ls. The tight lsa is what gives the sound. I have a solid roller that i couldnt use because it wouldn't clear the connecting rods i wanted to use, that has a 104 lsa. I'm betting that would have a radical idle.
